6:15 a.m. or 6:15 p.m.?
Are you asking about your home airport at the beginning of your trip or Orlando International at the end?
I'm an experienced, frequent flyer. I'm allowed to bypass long lines at the airline counter and at TSA security. Even so, I try to get to the airport 2 hours before scheduled departure. Flights board 30 minutes before departure.
It's not that I always need 90 minutes before boarding. Usually, I'm at the gate way too early, so I have a meal or a cup of coffee and I read or use my laptop.
However, the time cushion means that I'm still there on time, even if something goes wrong -- whether that's a traffic jam going to the airport or delays anywhere else in the process.
If you do not make it onto your flight, the consequences can be awful. And you can't blame the airline or the TSA, even if their lines caused you to miss boarding.
When returning home, Disney will assign your Disney's Magical Express (DME) pick-up time. If your flight is at 6:15 a.m., you won't be able to use Resort Airline Check-in (RAC), but if it's at 6:15 p.m., you can use RAC earlier in the day during RAC hours.