Where in Norway? DoubleTree (Hilton) is only in Oslo:

http://hilton.com/en/hi/promotions/h...rdic,scandiurl

If you're going to Oslo (either only to Oslo or at least as part of your trip), that's your best bet for credit cards, since you can get a bonus for both the HHonors Amex and the Citi HHonors card, and in fact you can probably apply for two Citi HHonors cards (with the 50k bonus if it's still around; see the MilesBuzz! forum for that) at the same time with the "two browser trick". So with 2 cards you'd have at least 100k-ish points, and with 3 cards you might get to 150k-ish points.

Club Carlson doesn't have a card yet. It's coming late in 2012, but we don't know what signup offers or earning rate there will be, I don't think we're even absolutely sure which bank it will be yet!

Too bad you seldom stay at hotels in the US. The very very very best way to get hotels cheap in Norway is to stay in cheap suburban Choice hotels (Comfort, Quality, Sleep) during a promo like the current stay 2 times (not 2 nights, but two separate stays) and earn 8000 points. Most Choice hotels in Norway are 16000 points a night, so 4 cheap stays here gets you an expensive Choice hotel in Norway, so sort of pays for itself (though maybe a bit hard to justify if you don't have a "natural" need for hotels in the US).

The problem with Choice and Best Western is that they both have fairly low signup bonuses, can't be easily churned, and earn very slowly from the credit cards (unless perhaps you have very high annual spend), except when used at their respective hotels (but agian, if you rarely stay in hotels in the US, that doesn't help you!).

I'm personally fortunate that I "naturally" need lots of stays in the US which can be done in cheap suburban Choice hotels, and in fact my #1 reason for using those is because it can then get me into $200-$300/night nice Choice hotels out on the fjords of Norway as a "side benefit" to my needed-anyway US hotel stays. I don't know how I would afford Norway (beyond Oslo) if I wasn't doing US hotel stays that I could steer to Choice during those promos. (And it's the fjords of western Norway that pull me back over and over and over again to Norway, not Oslo repeatedly.)

Some people use an annaul (very short, as in minutes or at most hours long!) sale on bying CHoice points from Discover America to fund their overseas Choice stays. I know nothing about that except for reading a bit about it on FlyerTalk (since I earn all the Choice points I need from actual hotel stays). You may want to search the Choice forum for "Discover America" to see if this is a worthwhile plan for you or not.

Even the Choice card signup bonus that looks half decent actually requires a hotel stay for a good part of the bonus. Having said that, at least it will get you a night or two at Choice, I think. The Best Western card sign-up bonus will get you only a night in Norway at best.

And then you'll be all used up. Since these cards aren't churnable, what will you do for your next trip to Scandinavia. (This chain hotel pattern isnt'unique to Norway, though perhaps exaggerated there. If in 2014 or 2015 you want to go to another Scandinavian country, you may need the hotel chains, but by then you'll have used up your non-repeatable signup bonsuse!

So the flaw in the plan to rely on signup bonuses is that (with many hotels, except perhaps HHonors through the Citi Visa), you can't repeat it for your following trip.

(I want to treval again and again and again, so I tend to focus on what's repeatable, vs what's one-time only. And in fact, every visit to Norway makes me want to do two more visits to Norway!!!)