I lived in Florida for 5 years, about 15 minutes from Disneyworld. Best time to go is in the spring or fall. Orlando gets too fucking hot and humid in the summer. Those commercial scenes of happy people running around Disneyworld definitely aren't in the summer. Then you just see tired, hot, soaking wet with sweat, miserable people standing in long lines. If possible, you might also want to try to avoid the times when everyone has vacation, or at least look into when the local schools have, for example, spring vacation. It gets real crowded then.

It was 20 years ago that I lived in Florida so I'm sure a lot has changed. There's a lot more to see now. You're into hiking though so you might want to try out the Florida equivalent. About 20 minutes North of Disney is a place called Wekiva Springs State Park. Instead of being mountains, like most parks out here, it is a swamp. They have miles of wooden walkways that wind through the swamps. There's also one area where you can go swimming in a huge spring. It's crystal clear water and you can see perfectly down to the bottom 20' down. The best thing is that you can rent a canoe and paddle down the river. It's a total jungle scene with snakes, alligators, turtles, and other critters around every corner. Yeah, it is a bit freaky when a big ol' gator swims so close you can reach out and touch him but it will be something you'll never forget. Just don't fall out of the boat