Hi!
One of the most crowded times of the year. The week after Christmas will be shoulder to shoulder crowds, but lots of folks love the time of year and do not mind the crowds
I really like it between Thanksgiving and Christmas - all the decorations are up, there is Mickey's Very Merry Christmas Party and it's very festive. There can be crowds, so it's lots of fun - just not shoulder to shoulder.
If you'd love New York City on New Year's Eve then you'll love the week after Christmas at WDW
Have a great trip!!