Christmas parade is usually filmed the first weekend in December, probably December 1-2 this year.
I would call this more of a low to moderate crowd time, however, the onsite resorts book very quickly - Disney VISA and Annual Passholder discounts were just released for 9/30-12/23, I expect discounts for the public on 8/16.
If you want to go then, I'd book it ASAP.