The worst place to refuel near MCO is, in my opinion, anywhere near MCO!

I almost always rent from Alamo, Thrifty, or National when I'm in Orlando, and I've always been able to refuel at gas stations in the Disney area (the Hess stations on Disney property tend to have reasonable prices), before heading off to the airport. It's a trip of about 25 miles, and if one fills the tank to absolute capacity, then when you arrive at MCO the gas guage will still be on F.