On the draft version of our 2007-08 calendar, schools are set to open to students on August 22nd. I believe the earliest they can start is August 20th due to a new state regulation going into affect.
I would definitely try to go after schools restart, and also keep in mind that the blackout dates for the FL resident seasonal pass lift on Aug 16th, so I would expect those days (Aug 16 - 20) to be busy with residents. I'll be there too if I can figure out how to skip a family function!
HTH