Well, the following started as a short post and then my mind started racing along and it turned into a 64-team P4 domino effect plan. Some serious offseason mental masturbation needs were satisfied.
When I look at the B1G and its setup with member institutions (AAU universities except for Nebraska, large state land grant universities, geographic connection), expansion that makes the most sense is adding Kansas and Missouri. It's the one conference that could take a team from the SEC without it being a pay cut. I think they would prefer OU and UT for obvious reasons, but I'm hoping it's KU/MU that becomes the reality. It makes a hell of a lot more sense for getting this stuff organized the way it should be.
So, if that were to happen, the SEC is the next mover that would make sense. With the GOR extension of the ACC, it's hard to see them go raiding there. That would mean looking at the Big 12. Again, they'd make a play for OU and UT. But do those schools really want the academic affiliation? Seems like it's not a great fit, especially for UT (plus aTm & Arkansas would fight against UT tooth and nail). But the SEC wants those Texas televisions and recruiting grounds. I'd guess they end up with OU, OSU and Baylor. This would, again, give the map some great symmetry with a 16-team conference.
Basically, what you see below but swapping UT for Baylor:
Which brings us to the ACC. Notre Dame could stay independent or, if it joins a conference, is locked into choosing the ACC. Frankly, the ACC should drop Wake Forest as a member but I think that's out of the real of reality. Assuming Notre Dame is added for a 15th, UConn makes the most sense for #16 considering academic strength and how much the conference values basketball. However, if we look at rivalries, WVU may make even more sense than UConn. Syracuse already has a partner in the Northeast with Boston College. Pitt's traditional rival is WVU. Louisville sits out there kind of alone but pairs for travel with Notre Dame & West Virginia bridges the rest of the geography. Plus, after the loss of Maryland, WVU probably helps get back into that state more strongly for recruiting and boosters. Last, this is always primarily about football and WVU is a stronger play than UConn by a country mile. So I'm going to assume Notre Dame plus West Virginia to the ACC.
So this leaves the Pac-12 expanding to a Pac-16. Kansas has been taken off the board, as has Oklahoma. So we're looking at graduate research, media markets, and trying to make geographic sense. My suspicion, despite my desire to believe otherwise, is that the schools within the footprint that make the most sense are non-starters due to some mix of politics, not being additive to media market, and lack of academic research opportunities. Texas is the key. And I believe that UT will want to have a pod it can dominate. So, in this scenario, I think we lose the opportunities for SDSU, BYU, Boise State, UNLV and New Mexico. Instead, we end up with a Texas pod of UT, TTU, TCU and UH with the Longhorn Network becoming the Pac-12 Texas channel through a deal that would have to be worked out with ESPN & UT.
Pac-16:
California Pod: Cal, Stanford, UCLA, USC
Northwest Pod: Oregon, Oregon State, Washington, Washington State
Mountain Pod: Arizona, Arizona State, Colorado, Utah
Texas Pod: Houston, Texas, Texas Christian, Texas Tech
And now we have our 16-team P4 conferences. Some good programs left out, for sure.
Someone will probably try to cobble together an "American" conference that could make a case for a P5: UConn, Cincinnati, East Carolina, UCF, USF, Temple, Boise State, BYU, SDSU, Fresno State, Memphis, CSU plus 4 more to get to 16 (probably look at UTSA, SMU, Tulane, LA Tech, UAB, UNLV and others).