Kim,
Thanks for your question!
Basically the first three weeks of November are historically what I would describe as having light to moderate crowd levels. But as you get to the week of Thanksgiving, the crowds get extremely large. They are probably only second in size to the Christmas holiday crowds. You should consider the busy November season as running from the Saturday before Thanksgiving through to the Saturday afterwards. As for the very lightest days, I think the earlier in the month you go, the better, knowing that the weekends are busier and the weekdays are very light.
Two items to remember for your overall planning are the two big events underway at the parks. In
EPCOT there is the
EPCOT International Food & Wine Festival that will run right until a few days before Thanksgiving. This causes big weekend crowds in that park, to be sure. Over at the
Magic Kingdom Park, starting in early November, is
Mickey's Very Merry Christmas Party. This will close down that park on select evenings to only those with the special event tickets. So you will want to either plan to attend, or ensure that you know what nights you can go to the Magic Kingdom without this event keeping you from enjoying the park in those magical evening hours.
Write me back if I can answer any follow-up questions!
Have a Magical Vacation!Doug