We have been there twice on the 4th, both times were crowded but tons of fun. Since we usually get up and go to the parks early we are back at the resort by noon or 1, swim/relax until later in the day. We always have a PS and usually go to Epcot for the fireworks. Since its a Holiday the hrs are pretty long and you will have plenty of time to do what you want to do.
Denise