I believe the "thermostat override" is only to override the motion-detector which keeps the A/C off when you are not in the room. If you must have 70-degree air when you first walk back into the room, I guess that might work.
I've also heard dancing the "Hokey Pokey" works.
My experience has been that no matter how warm the room is when I return from the theme parks, it cools off to a very comfortable temp in a matter of just a few minutes. We've done a lot of trips and never been uncomfortable.