It's about a 30 min. drive to MCO. Is your rental car on property or do you have to use shuttle back to airport? If you leave the Contemporary by 9 AM
that would have you at the airport around 9:30. If your returning car on property that only takes couple minutes, then just walk to terminal. If you have to use shuttle allow and extra 15-20 min leaving Contemporary 8:30AM.
If your checking luggage use RAC service at your resort and get your boarding passes, then you can go straight to security after returning car.
I would use 417 to drive back. There are two 1.25 tolls. You can fill your tank at the Hess station across from the Caribe Royal (on 417) Then take the airport exit (Boggy Creek Rd) turn left, and your couple miles from airport.