My family (wife, DS 5, DD 2) are going also from 12/26-31. I am so excited. I always wanted to see the decorations and we were fortunate to have gone in May and bought extra tickets with the no expiry. So tickets are out of the way. We got the great HI rate, so that $10.00 is put away.
We are going with a totally different mind set for this trip. We know the crowds will be rough, but we are going not so to ride rides, but to take in the little things we always skip. Resort hopping to see the decorations, more ADR to enjoy different foods. As long as you have the mindset that it will be crowded, you still can find the Disney magic. Good luck.