Here is my crazy scenario: Big10 goes to 20 and splits into four five team "pods. The Big10 takes in Texas, Oklahoma and Kansas from the Big12, Colorado from the Pac12 and UConn from the AAC. That leaves one Eastern school. Since I believe that the ACC is untouchable and there is a limited amount of quality NE or Mid Atlantic schools not in the ACC (Buffalo? No. UMass? LOL. Cinci? OSU would never allow it), my only conclusion is . . . WVU. I know in real life it would never happen, but this is a crazy CR scenario.
Pod A: Maryland, Penn St, Rutgers, UConn, West Virginia
Pod B: Indiana, Michigan, MSU, OSU, Purdue
Pod C: Illinois, Iowa, Minnesota, Northwestern, Wisconsin
Pod D: Colorado, Kansas, Nebraska, Oklahoma, Texas
The pods each form a ten team division that rotates each year and the two divisions will play in CCG.
Year 1
Pods A &B: Maryland, Penn St, Rutgers, UConn, West Virginia, Indiana, Michigan, MSU, OSU, Purdue
Pods C & D: Illinois, Iowa, Minnesota, Northwestern, Wisconsin, Colorado, Kansas, Nebraska, Oklahoma, Texas
Year 2
Pods A & C: Maryland, Penn St, Rutgers, UConn, West Virginia, Illinois, Iowa, Minnesota, Northwestern, Wisconsin
Pods B & D: Indiana, Michigan, MSU, OSU, Purdue, Colorado, Kansas, Nebraska, Oklahoma, Texas
Year 3
Pods A & D: Maryland, Penn St, Rutgers, UConn, West Virginia, Colorado, Kansas, Nebraska, Oklahoma, Texas
Pods B & C: Indiana, Michigan, MSU, OSU, Purdue, Illinois, Iowa, Minnesota, Northwestern, Wisconsin
That's 9 conference games with no crossovers (the Big10 already has that). Each team gets to play every team at least every three years. It still keeps the two division requirement for a CCG (nothing says that the division have to be static from year to year).
Obviously, I would include some ACC if I thought they were remotely possible, but I don't think they will be by 2024, if ever. WVU is already a P5 program and has had success in the OBE. They fit the regional aspect of the pods and have past relationships with Rutgers and UConn. Obviously, Colorado is a stretch as well but to get back with Oklahoma and Nebraska would be huge.