A few things to consider:
Because of the library pre show, the wait for ToT is at minimum 15 minutes, plus the ride time of 5 minutes. (20)
DHS closing at 7:30 means that everyone is heading for the exit or Fantasmic. You will be walking against Fantasmic crowds. 15 minutes to get out of the park. (35)
5 minutes for the tram car to get you to your car (40)
Another 30 minutes in car traffic to get to Buena Vista Dr(70)
10 minutes drive to Ft Wilderness parking lot (80)
10 minute wait for internal bus (90)
5 minutes on the bus. (95)
With a FP at 7, you'll arrive at 8:35, if you're lucky. Check in for Hoop De Doo is at 8:15.
If you leave at 7, you'll get there early though - because the crowds won't be leaving yet and there won't be traffic.