2 20 team superconferences being left standing at the end of the day doesn't seem that unrealistic at this point.
SEC + TX/OU + 4 ACC pickups (Clemson, Florida State, Miami, and UNC or BC)
B1G + ND + Kansas* + 4 PAC Pickups (USC, UCLA, Oregon**, Washington)
Then everyone left over scrambles to reshuffle into something that makes sense as a second tier (mostly the left out P5 schools) and a third tier (everyone else). But question whether the SEC and B1G don't just become their own league and say FU to the NCAA at that point. Also possible a couple of the B1Gs get jettisoned here (looking at you Rutgers and Maryand) in favor of others.
*I'm including Kansas instead of a 5th PAC for a couple reasons: basketball, KC TV market, splits some of the geographic difference. They're terrible at football, but with the other shifts, they could maybe attract some better talent away from the next tier of schools.
**Because Nike.