I don't see the remaining top Pac-12 brands going anywhere soon.
Oregon and Washington to the BigTen? Sure, if an invite comes their way, but they aren't joining the Big XII.
Same for Cal and Stanford. The only move that is appealing is the BigTen (which is very unlikely).
Keeping those 4 Pac-12 core members will likely prevent the others (Utah, Colorado, Arizona, ASU, Oregon State, Washington State) from bolting for the BigXII.
The key will be the upcoming Pac-12 media deal. If the numbers are close to the BigXII and ACC, they will likely survive and even expand with SDSU and UNLV. Personally, I don't see Boise State offering a large enough fan base or media market to make it an appealing addition.