Is it possible that it may have similar runway performance to the 747, despite the obvious size and weight factors?
I seem to remember reading that Airbus were claiming similar takeoff performance on a 'typically' loaded aircraft, but I'm damned if I can remember where this was written. It could of course have been marketing exuberance.
If that is the case that's one half of the hypothetical question answered. That being said I'm sure there's alot of infrastructure associated with an aircraft this size and that will probably be the biggest obstacle.
I'm curious to see how well it stops. There must be some fearsome energy being transferred to those brakes, even with the spoilers and 2 reversers working.