6AM flight is tough! But I'm in the 2 hours prior group for domestic flights, and it's worked well for us over the years, even at MCO. The good news is there's likely going to be less foot traffic at the airport that time of morning - the bad news is they might have less staffing to get your through security. But you should be just fine with 2 hours (I wouldn't do any less than that, though). Not sure that it matters, but there's probably not going to be a lot open in the terminal at that time of morning for breakfast or snacks, so that might need to be part of your morning plans, too! Safe travels.