In Orlando when you ride in a car service vehicle the driver will pick you up 2 hours in advance of the departure time of your flight. That has worked well for the past 15 years and continues to work well to this very date. I have probably taken over 7000 families back to Orlando in the past 16 years, all 2 hours before departure, and none have come back to me saying they missed their flight. If a family wants to get to the airport earlier than all they do is say something to the driver or company when the subject comes up. I have never seen anything in writing about recommendations on how many hours you arrive at the airport before your flight.
I just went to the Delta website and they say, at MCO, you have to check-in with Delta 45 minutes before flight and be at the gate 15 minutes before flight. That total time is 1 hour. At Orlando most car services drop you off at MCO 1 1/2 hours, 50 feet from the Delta ticket counters, before departure. I am sure it doesn't take over 5 minutes to walk to the ticket counters.