I don't think Burning Man will ever have a true September. There's no amount of money that can make it perfectly safe and comfortable, and it takes rather a large amount to make it even modestly so, at least by the standards of the wealthy.

Driving in is slow and boring. Flying in is fairly dangerous. Even if the event itself can be made perfectly comfortable with enough money -- and it really can't -- at least the journey will always suck a little, one way or another.