Some 33% more space for $55, could work (2nd option, Portofino)... I'll wait for some advice...
If you can get your Loews Plat, you might be able to upgrade to the Deluxe room at the Hard Rock. So that might be worth looking into. But the Portofino Bay rooms are very nice. Note that your reservation will have a 3 or 5 day before arrival cancellation clause, your CC will be charged one nights room and taxes when you make the reservation. If you cancel before the cancellation fee hits, then the charge will be reversed. They are pretty good about this. Many times, I've called and changed my reservation dates and even hotels with no problems.
Hotel accomodations:
- Would make the reservation for 2 adults as most charge a huge differential for "registering" extra adults. No problem at the WDW Dolphin (too big to control), would I get problem at Universal properties?
As long as you book a room that officially handles 4 or 5 adults (i.e. 2 double or queen beds), there shouldn't be any extra charges. Plus, every person in the room gets a key with their name on it. So if you want them to have the "Express Pass" keys, they need to be registered and have their own keys. This could be an issue when you want to split up with the grandparents as you mentioned.
Travel Plan-
We are thinking to switch from the WDW Dolphin to an Universal property on JAN/7, giving us 2 nights, 3 days at Universal. We would have stayed at the Dolphin while doing Universal but the Express benefit is a plus as we want to do Islands of Adventure while the kid does Universal Studios with grandpa and grandma.
One thing I have done in the past when trying to do both parks is to keep our offsite hotel and still make an onsite reservation. We would check-in, but not move out of the other hotel. This would get us two days of Express Pass access, but not the hastle of moving all our stuff around. This worked for us at the time due to my having a Preferred Annual pass, therefore no parking fees. Also, we were on a Marriott 7-night award which came with 7 nights, therefore there wasn't a lot of "savings" by checking out there. And the Univesal onsite hotels used to have some very good off-time rates around $100 or so, even for one night stays. Unfortunately, they have gotten wind of that deal and now they seem to charge a higher rate for one or two night stays. The rate comes down the longer you stay onsite. This may not help you for your upcoming trip, but keep it in mind if in the future you come again.
Would you go to wet 'n wild? Or shall I leave this for july?
While I do believe that Wet 'n Wild is open even in Jan and the water is heated, I still agree with Mary. You will be cold, even if you hit on a warmer January day.
I also agree with Mary in that NYE is a horrible day to go to Disney. My wife and I came down a few years ago when Tennessee played in the Capital One bowl game. By the time we tried to get into a park, only Epcot was still open to the public though it did close soon after we made it in. Even though we made it in, we couldn't really do anything it was so crowded. You couldn't hardly walk around there were so many people there. I have been to the parks a few days after New Years and the crowds are much more manageable.