We went October 29 - November 4th this past fall. Be careful not to avoid Jersey Week as that DOES affect crowd levels. I googled a New Jersy website that showed the dates of the state's annual teacher's conference, it's a perfect time for families to take off and head to WDW so the crowd levels go up that week.
We avoided MK on Halloween which was Monday, went to MGM instead which was empty, and then Epcot which wasn't bad either - only wait was for Test Track and Soarin, but not bad. Avoided all the extra magic hour parks. On Tuesday morning we had an early character breakfast at Crystal Palace, went straight to Fantasyland and rode every single ride without a wait. Well maybe 5 minutes for Dumbo and the carousel but that's it. Have NEVER experienced that before. It was wonderful.
I wore a jacket tied at my waist because by evening I needed it. And alot of the attractions have AC that is a little too cool for my comfort. The jacket came in handy several times.
Have fun!