Are you sure you're not talking about Supercon this past summer? The dealers room was disgustingly hot all three days. Megacon never has an issue with air conditioning but the crowd is always insane. I haven't been able to get around the dealers room on Saturday for the last four years I've gone.
I suggest Megacon if moot ever goes to Florida, Supercon has massive organization issues (bad venue, no parking, poor staffing) and Metro, while a good alternative, would turn the panel into a /hsg/. Also Metro is smaller.