I have to vote for November. Thanksgiving time is nice, but very crowded. A great time to go is during the first 2 weeks of December. Crowds are very light and enjoyable. The resorts and parks are decorated to the hilt and there is so much to see and do, such as the Candlelight Processional at EPCOT (this is a must see), different Santa's at the various World Showcase pavilions, the decorations and gingerbread designs at the various deluxe resorts (make sure to get over to see the one's at the Boardwalk, Yacht & Beach Club resorts). This past visit the temperatures were in the mid to high 70's to low 80's during the day during almost the entire trip. The last weekend I was there it did get cool and a high of about 60 degrees. The Wilderness Lodge is a great resort and is absolutely beautiful decorated for the holidays. I saw several families taking pictures in front of the tree in the lobby to send with their hiliday cards. Make sure to take some time and relax in the lobby. Don't forget to get the free refill mugs (used mine several times a day). For a fun time, rent a couple of watermice and head over to the lake by the Magic Kingdom. When you check in, don't forget to ask about being the flag family (but don't be surprised if there is no/limited availability -- I was there for 8 nights and the only day available was the day I checked out and since that was going to be at 4am, that took care of that). Oh, and don't forget to get the hidden Mickey list from them too.
Below is a link to the many pictures I took on my last trip and there are several of the various decorations and resorts (including gingerbread displays from the Floridian, BC, YC, BW, Contemporary & AK Lodge). There are also pics of the Wilderness Lodge & the room I had. The views from this room were AMAZING!!!