We just got back from the Dolphin and requested a late check-out on 1/16. They were willing to go as late as 2:00 for free. Anything else they would charge $30.00. She did mention that they had a large conference going on.
In retrospect, I wish we would have paid for a late checkout. Our flight didn't leave until 7:00 pm and we debated between taking it easy at the Dolphin our last day (swimming, miniature golf, etc) or going to Sea World (ugh!) We decided on Sea World just because if we were going to be at the hotel I would want access to our room after 2:00 and hated the thought of paying for it. At the time it seemed easier to go to Sea World, which DH and the kids enjoyed, although I guess I'm not a fish person. Give me Disney any day!