My vote would be early December too!! I love going from Thanksgiving day through the first week of December. The parks are beautifully decorated, you can go to the Mickey's Very Merry Christmas Party, Epcot has the holiday storytellers in all of the countries, the tree lighting in Epcot, the lights of winter are pretty there too.. There is the Candlelight Processional in Epcot, the parade in MGM and AK have Christmas themes, Downtown Disney is decorated too, santa is there, all of the parks have their own huge themed christmas trees.. MGM has the Osbourne Spectacle of Lights.. millions of lights along the Streets of America..
Ive been there the past 2 Thanksgivings- into December but cant go this year. Im sad.. I love it there decorated for Christmas!!!