We went the same time last year. It wasn't terribly crowded and the Christmas decorations were great, especially the Whos in Whoeville at Seuss Landing in IOA, but if you can stay at one of the on-site hotels, you get the front-of-the-line (FOTL) privileges with your room key card that can't be beat. Even if you don't stay on site, you can buy the FOTL Express Passes. The FOTL from the on-site hotels is better because it is FREE and for the most part, you can use it an unlimited number of times, as opposed to the Express Pass that you purchase which I believe is only good for one time on each ride.