So let's say Arizona bolts tomorrow no way it doesn't take a week for ASU to follow and then Utah has to make a decision. I think Oregon and Washington have more time to vet the situation but they will be on the clock.
I don't see the PAC surviving Arizona, ASU, Colorado, UCLA, USC and Utah leaving even if Oregon and Washington seem to want to stay. There just aren't the teams out there that can cough up to 30mm to join the PAC on what would be a gamble at this point. I guess it isn't out of the question they could invite 6 teams from the MWC and fold that league. It would probably look like something like the below:
SDSU
Boise State
Air Force
UNLV
Utah State
Colorado State
The problem is no way they get anywhere close to B12 money at that point and Oregon and Washington would be gone.