When I grew up in Las Vegas, every year we would go to Disneyland around Halloween, because Nevada has its state's day on Halloween, and we got off from school. When I was younger, it would be really empty, so as an adult I continued going in October (all different times of the month) with my kids and DH. I have noticed each time, it has gotten more and more crowded no matter when in October, and so we are trying September this year.
I am just really excited because by the schedule on DL, we will get to be there one day with HM before they close it down for refurbishment on the 12th. We thought we would totally miss it altogether!