Just confirming that Google doesn't have any such venues in Zürich. The
biggest meeting room is about ~150 people. OK, maybe more, I'm bad at
counting, but it doesn't compare in any way with the rooms that we had
at previous DebConfs.
On top of that, having that many guests for an entire week would be
somewhat troublesome, with all the security and "not allowed to wander
in the building unaccompanied", etc.
Sorry :(
PS: I wouldn't have any time at all to help with a Zürich bid, and I
personally also prefer off-town.