general idea for ga line-up is 8-9 in the morning. you may decide to sleep out, but no one knows if they're going to allow that by the arena... but the centre is out in the middle of the city, so i don't know how they could stop you.
as was already said, union station is right next to the air canada centre... as with any train station and/or mass transit hub, you often see people sleeping while waiting for their train. thus then, it is a viable option to stay at the train station, catch some Z's, and wake up early enough to just walk over to the arena at 7, 8 in the morning.
as for an official statement from either the band or the arena regarding GA lineup? there is none.
all of this information is very easily gotten with just a 2 minute bit of research, and/or common sense.
i'll now go back to being witty.