I'd save it for the trip. It makes for such a fun trip when you know you don't have to worry about money so much. I always have such a better time when I travel when money isn't an issue (it's rare but it happens every now and then). I can buy things in stores I see, eat at nicer restaurants once in awhile, have two cocktails instead of one, etc. It's the little things that make have the extra $$$ worth it.
As far as upgrading on a hotel room, if it won't take up all of your money, I'd try and get at least a non-shared bathroom room, especially since you and your honey will be spending more time than the average bear, uh, getting reaquainted. But I wouldn't blow a substantial portion on a super nice hotel room because, really, who cares? D's got it right. Clean bedding, towels, and hot water are all that is really necessary to enjoy a stay in a room. (Just don't forget your antibacterial wipes, kay?)