Cal and Stanford need to wait for the ACC to make an announcement. They will wait as long as they need to because that is their only lifeline for a P4 conference.
If they are turned down by the ACC conference, then, in my opinion, before making a decision, they will need to have talks with the AAC and the MWC. The talks will revolve around television revenue of the conference if they decide to join. I don’t think there’s any guarantee that any of the four pack 12 conferences will join the Mountain West, if they can get more money from the AAC. Then it will revolve around that money and travel costs.
Stanford and Cal don’t need to make any decision about their future until they run up against deadlines about making an independent schedule. Both the Mountain West and the AAC would take either or both with no delay. When BYU went independent they announced on August 11. There were three teams on their schedule for the following year. They believed they would end up filling their schedule with WAC teams until they could get it better under control the following year.
As has been said before, Washington State, and Oregon State don’t have a lot of bargaining power here, and most likely will go wherever they can get the most money.
Therefore, I see this taking some time but not months. The ultimate deciding factor being timing of an independent schedule.