Thanks. Previous posts said 40, but that may just be per group/tour guide. They may have multiple tours per day of 40 people max each.
I'm not going this year

We just went to Disney last month. I am starting the thought processes for next year or 2017. I was curious if people were getting choices that worked. It would be a bummer to book air, hotel, and ADRs 180+ days out, and then find out that the weekend you are there isn't available. It would require a lot of rejiggering of plans. I guess you just have to plan for it both ways: doing or not doing the tour.