Update - just a note on our parade experience on Mon., Dec. 8.
It was a Zoo!
Yes, they did film for the entire 4 days this year. According to the guide on our Keys to the Kingdom Tour, the previous week, the 2 extra days were because of scheduling problems from one of the parade "stars".
My brother-in-law was able to do the Train Tour that morning before the filming began. By the time we got there about 10 AM it was raining buckets. With the construction around the hub area and the whole front of the castle area blocked off for filming, the foot traffic congestion was crazy. We did a little shopping in the Emporium and went to our Plaza ADRS. Thank goodness the food was wonderful and the restaurant was only half full (could it be no one was able to get through the crowds?)
And then we left. No 7 Dwarfs. Nothing else. Too many wet, miserable people. We went back to our villa and threw our sopping wet clothes in the drier and played cards until it was time for our Ohana dinner.
Side note - the director from the filming kept having to shout "Look Happy".