Delta Airlines is headquartered in Atlanta and has a significant presence which may allow for more flight options. That said, all major airlines have many flight options in and out of the Atlanta area to destinations across the U.S.
Remember, when making reservations, Monday is our backup date for competition should Saturday or Sunday's events need to be postponed due to weather or any other reason. I do not recall an event where Monday has ever been used, just an FYI that the park has been reserved for a Monday finish, if needed. Rain alone would not cancel the event, however a significant weather event could.