We booked August 13 - 20.
Last year we were there from August 19-29. The only park that I thought was a bummer as far as crowds go was the MK. Epcot and MGM were OK - not empty, but OK. I don't even remember AK, as it was sooooo miserably hot there that day is a blur.

The greatest thing about August is the rain EVERY day - it really clears the parks out. Going back to the parks after dinner time was awesome.
Anyway, I was hoping to go as late in August as possible and because my high schooler son starts a week before the grade schoolers, the 13-20 was it for us. Now I am kind of happy because we will be missing the
free dining and the crowds that plan may bring.
I just changed my AP ressie from Poly concierge to GF with no problem yesterday. I am hoping that is a good sign!!
We can all keep our fingers crossed for low crowds - you never know.
Lives4Disney