In an absolutely humourless way of analysing this situation, I am able to extract the following information from your post:
1. The hotel online booking system made a mistake of double booking and was unable to accommodate your family in one cabin during the period of your stay but they are have two different cabins available hence requiring a move mid-trip.
2. You booked "non-refundable" flight tickets so changing dates for the trip is out of the question unless extra cost is incurred (rebook ticket).
3. The hotel offers you credit amounting to 15% of total bill. YOU ACCEPTED, knowing a move is required BEFOREHAND.
3. You are not happy to move cabin midtrip as your family will be "cabin-less" for 5 hours.
4. The hotel offers your family a hospitality suite to relax in if you plan to "veg" during your cabinless period or actively seek your advice to plan activities ahead so you will not feel "homeless".
5. You are unhappy now, in spite of knowing a move is required beforehand and accepted the hotel's compensation.

My advice:
1. Next time, ask the hotel how long you would be "cabin-less" for if a move is required. If you don't find it agreeable, then NEGOTIATE and don't accept the compensation.
2. No reason to feel frustrated or "cheated" after you have accepted the hotel's compensation. You should have well considered the situation of cabin move BEFORE you accept anything from the hotel.
3. Ultimately the hotel's online booking system is at fault. If you don't find your cabin move acceptable, then CANCEL your stay, or book another room category. A brief look on the hotel website shows they have a whole range of accommodation available.

Anyways, the hotel is not lying about one thing, the hospitality suite does have a stunning view
Hospitality suite view

With one lounge chair for the whole family!

hotel was only clear at last minute. this is why some here deal with management level, to help avoid lack of clarity.

that could be a problem.

I agree that this is key and that ultimately, the hotel (via the faulty reservation system) was the root of the problem.

That said, the OP should have been wise enough to get a firm time frame for the move. The fact that she didn't IS actually her fault and by not doing so, she agreed to the default check in / check out times (and this is 11am/4pm, I believe). I find it odd that she would not press the resort on this point, since it clearly seems to be very important to her.

Now, if the resort promised her a condensed time frame for the move ('we will have you out at noon and then back in by 2', for example) and then went back on this offer, it would be a different issue. But this does not seem to have been the case.

Given all of this, I don't think the OP should expect anything else at this point. And I agree with others about the options: cancel the last night, cancel the entire reservation, seek an alternate accommodation at the resort (which seems to be available), or just go with it and enjoy the 'homeless' time.

one management level suggested shorter time frame, it seems to me. (didnt sound like normal/published 5 hour to me.) concierge is not management and cannot say anything other than published. this is the problem with not dealing with management. the question of what the REAL minimum time frame is needs to be directed at management, with negotiating taking whole situation into account.

management are the decision makers (varying by position) while anyone else may have a little bit of flexibility given to them, but they cannot make executive decisions or promises.

I didn't see this in the OP. Can you point it out?

I admit, I find this poster's writing style a bit hard to read, so I may have just missed it. If management initially indicated a condensed move time frame and this was later changed, it alters the entire situation, IMO.

Yes, here you go ...

The emphasis added is mine, but it does seem a Reservations Manager first dealt with her, and then only recently did she get an "itinerary" from the concierge indicating the standard check-out/in times.

Absolutely agreed

Thank you all for the suggestions, I haven't checked the website re: lounge amenities but am now most intrigued! I appreciate the experienced and helpful opinions of FT from various geographic and demographic perspectives. I called the reservations manager today to confirm our itinerary and ask that she coordinates our move with the activities concierge to ensure the "seamless"transition I agreed to when I accepted the (just under) 2k credit on our stay for the cabin switch. We are looking forward to our trip, I sense the resort relies heavily on seasonal help and has just expanded significantly under new management... A few communication blunders and system glitches is no match to the incompetence and incivility of the Winvian crew. Robyn, you are quite right to deduce that our family is (relatively) new to luxury travel. Whatever happens at "Paws Up," we've booked the hot air balloon ride at Amangani and that should be awesome- to which our 7 yr old son asked my husband, "but will I be able to hold your hand and bring snacks?"
Now... That's our idea of a chuckle thanks!
Here's to peak experiences!

I hope it all works out well for you and that you have a great time (at both places). We'd certainly love to hear your feedback on both properties once you return.

We were all new and young once (unless we grew up in the "lap of luxury" - which I didn't). And I think that a property that purports to be a "luxury property" should be just that - for every guest.

Unfortunately - I have found that some properties don't act this way - especially when it comes to younger/inexperienced guests. For example - I recall arriving at the George V (under prior management) when I was in my early 30's. And the hotel said - we thought you were coming tomorrow - and don't have a room for you. But we have booked a room for you at our sister hotel (out at the airport). Now I was half-asleep - but didn't buy that for one minute . Walked out of the hotel - and stayed at the Prince de Galles (next door). Of course - it's harder to do that in the middle of nowhere in Montana .

OTOH - I once had a reservation at a "renovated room" at the Lodge at Vail - specified on my hotel confirmation. And - when we arrived - we were told. Good news - we can "upgrade" you to a larger place (unrenovated for 20+ years). We had paid 100% in advance - demanded a total cash refund - got it - and walked. Wound up somewhere in Breckenridge (pretty nice place) - Vail sold out.

I don't know if stuff like this still happens these days. But I do think that a luxury hotel should provide an excellent seamless experience except when it can't due to situations beyond its control. Without requiring a client to act as a lawyer in his/her own behalf - or to have a travel agent do that stuff for them. I often arrive in places many time zones away from home when my travel agent is sound asleep. Wouldn't think of calling him/her up at 3 am local time (when you get phone calls then - it's usually because someone has died).

With regard to your remark about seasonal help - I will add inexperienced/non-professional. I think it's pretty much that way in many (perhaps not all) properties in the mountain states - luxury or not. Just like every server in New York used to be a wannabe actor/actress - most service people I've encountered in that part of the world just aspired to be hot skiers.

As for the Winvian - probably the same issues with seasonal help. And - being from Florida - and having been to some of those "cutesy country" places in the NE US in the past - well those guys don't know how to do A/C right (assuming it's even possible to do A/C right in some old place that's leaking whatever somewhat cold air they can crank into a place faster than it comes in). It's honestly pretty hard to "cool off" in the summer - unless I go far away (last summer was Stockholm) - or am in a southern part of the US where we're great at A/C ^.

You take care. Have a great trip. Make sure the places you stay treat you well (without your asking them to). And report back. Robyn

Hello! We're back and still beaming with radiance of our brief time at Amangani... Glorious setting - the supreme "perch and tuck" spot of Jackson... Food presentation was delightful, inspired and flavorful. The service details were thoughtful and personal... And our Amangani suite was a true respite- I loved the patio, napped under the moon and stars with Aspen tree leaves rustling in the cool, clean air.
The suite could use a re-carpeting, the spa and fitness facilities were tiny but other than that.. An intimately luxurious spot which exceeded our expectations.
"Paws Up" is in a heavenly area, miles of sight under big sky with hay farms, cattle, horses, active river and endless activities. The location is quite remote and had we not had our own car to take private excursions for unguided hikes, trips to the "ghost town," and general exploratory interests- we would have felt sequestered. The resort upsells every possible guided experience to the international tourists and reunioning families who subject themselves to the tarp covered yurt communities just feet from the river... Communal dining and only chauffeured escapes... Is that glamping? Not sure but we were contented in a meadow cabin with outdoor hot tub and requisite golf cart. The cabin was cozy and had great views but the bed linen (60:40 cotton polyester), sparse housekeeping and overburdened but earnest service was not worthy of the rates... The redeeming factor was the food... Delicious and full board is truly all you can eat, whenever and wherever you prefer- this was fun for our family as we love food and treasure private family meals. The food was truly awesome, kids loved the duck, halibut, salmon, custom pastries, prime cuts of meat all seasoned to perfection... I can recommend the "Resort at Paws Up" if you take a private house (with requisite Kia) or cabin, stay two nights and eat well, white water raft and take family hikes... Then a night in Big Sky to break up the drive to Yellowstone and Tetons... and end at Amangani!
Great trip overall--
Oh, and the cabin move was predictably botched by the staff but the people are so wholesome, woefully undertrained/staffed... I just had a couple huckleberry vodka lemonades and booked us up on a few excursions.
Thanks, FT luxury hotel forum! Your advice is quite right and I appreciate your insights we look forward to future luxury travels as we surely "live the dream!"

"Predictably botched" - I love that! As well as the way a few vodkas and anything can ease the pain .

FWIW - I never much liked "middle of nowhere" places even when I was younger (luxury hotel staff who all aspire to be "hot skiers" are tiresome after about 15 minutes) - and don't go to them now. I very much preferred and still prefer big cities. Read this book:

http://www.amazon.com/Dave-Barry-Doe.../dp/0449908100

And put Japan on your travel list.

Thanks for reporting back. Robyn

Glad you had a nice time! I haven't looked at Paws Up in a while but you've peaked my interest. Got any pictures?

Hi Ericka, I posted pics under photos on my profile page (at least I think that's where they are...) it was definitely fun, if you do go- avoid late June/July as it is hot and they have Mosquitos. We had no Mosquitos for aug 9 arrival as the temps drop at night precipitously- makes for cool misty meadows in the morning. One of our guides was a U of MT law student from Missoula that worked at the resort over four years and mentioned that the camps are great in the fall but steam ovens in the hotter summer days. In retrospect, I would go over lower occupancy. If you are along foodie type, they also do master chef/wine pairing weekends that looked awesome.
Robyn... Thanks again! I love Dave Barry and Japan is on the short list