I have been both the beginning of Nov and the last week of nov into the beginning of Dec the week after Thanksgiving.It was more crowded the end of the month than the beginning but it wasn't overly crowded still had a great time and did everything we wanted just more people in the parks.Thanksgiving week is going to be extremely crowded but if you go in with a plan you should be fine just go in knowing its going to be busy/crowded and expect to have longer waits.