We have done this every time we have spent Christmas in Disney.
I bought a fiberoptic tree, about 4 foot, and bought extra decorations, ie disney, opened the box and put them all inside. Brought a skirt for the table and window clings. We had our stockings set up around the back of the beds. We set up the table in the room to be near the window and would turn the tree on. It was such a pretty sight to come every night and find the tree on. Even the CMs (room service) would make sure that everything was in order and plugged in. At the AK they had the kids do decorations on paper plates, etc., and we put this on the bottom of the window, along with the oversized Mickey hands.
We woke up on Christmas Day with a stocking on our door filled with Goodies from disney. I noticed them on all doors.
I had forgotten to gift wrap some things and I went to the resort gift shop and they wrapped each and everyone of my gifts, free of charge, and delivered them to our room (while we went to the parks) with the kids and placed them on the table around the tree. What a surprise when they came back to the room and saw the gifts.
We always get an extra decoration in DD and have it engraved with the kids name and year. This they love doing.
We also had the Santa Mickey Hats for the boys and the girls wore the headbands with the reindeer ears. On Christmas Day and Christmas eve everyone wore Christmas Theme sweaters or sweatshirts that were decorated at home with transfers, iron ons or sequins.
Don't be surprised to find people dressed up for New Years' Eve. We have seen them in formal attire (gowns and Tux) in the parks before heading out to one of the NY Eve's parties. It is so much fun.
