Here are a few of my times, returning to MCO....left 3 hrs prior to flight, and had about 90 mins to kill at the gate. Another time...left 2 hrs prior to flight, had to run to the gate as the plane was boarding. Another time....3 hrs prior, and had almost 2 hrs to kill at the gate. Most often, I'm sitting at the gate for about 70-90 mins, and that's okay with me. I can stop and grab a bite to eat, use the bathroom, whatever, once I'm through security.
Oh, in all reality? You need to be at the DME bus stop at least 15 mins prior to the stated pick up time. That p/u time is the time the bus should be leaving!!!