I don't know if it is allowed to stay at the airport over night, I don't think so.

Done that about half a dozen times and until now nobody's ever tried to throw me out...lol ;) But it's exhausting as hell, believe me that much. When I do it, I'm usually asleep before we even hit the runway. =P It sucks that there's no schedule posted yet (at least a tentative one), so we could check what we'd miss if we took the Sunday flights...