... what would it look like if we did?
First, we'd need to understand that without OSU, we're less valuable. Michigan and OSU are defined by The Game and the history of the rivalry. Remove that and you have something less, for each.
That said, any conference would still take us.
And our leaving the Big Ten would leave OSU no reason to stay; they'd probably be in the SEC in no time.
I think Michigan and Ohio State splitting up would be a tragedy for college football and sporting culture in America, but I'm playing along with a fantasy that Michigan were petulant enough to take our ball and go home. So let's run with it.
Like it or not, the academic associations matter to the University, so we're not going to the SEC or Big 12. The only option is the ACC.
People can call it a "dying conference" all they want, but the grant of rights has effectively prevented anyone from leaving.
If OSU went to the SEC, Penn State would surely follow us wherever we went. They, too, care about the academics, so would not be wild about the SEC or Big 12.
Adding Michigan and Penn State would revitalize the ACC.
Not only that, but with the ACC, weirdly, already having taken Cal and Stanford, the four other Pac-12 schools that jumped to the Big Ten would probably follow Michigan and Penn State, if their whole value proposition for joining the Big Ten were gone.
Michigan leaving would start dominoes falling that would quickly end the Big Ten.
The ACC becomes a coast-to-coast superconference that includes USC, Stanford and Michigan, which would finally probably be too much for NOTRE DAME to say no to. They'd play Michigan every year, and have Cal or Stanford on their schedule 4 of 6 years. They would get the national exposure they desire in a conference that spans from Miami to Seattle, from LA to Boston.
In this scenario, SMU re-thinks their decision to join the ACC and instead joins the Big 12, opening things up for Maryland to re-join UVA, UNC and Duke - where they have always belonged.
ACC West: USC, UCLA, Cal, Stanford, Oregon, Washington
ACC North: Notre Dame, Michigan, Penn State, Syracuse, BC, Pitt
ACC Central: Clemson, UNC, Duke, Virginia, Virginia Tech, Maryland
ACC South: Miami, FSU, Ga Tech, Louisville, NC State, Wake Forest
The SEC would have a quandary in that they'd want a second team to take along with Ohio State. And probably two more after that to get to 20.
Nebraska would be one. They bring that huge fan base, and you can reunite them with Texas, aTm, Oklahoma and Missouri.
After that, I think MSU/Wisconsin are the way to go as opposed to Iowa/Illinois.
So here's a new 20-team SEC...
SEC West: Texas, Texas A&M, Oklahoma, Missouri, Nebraska
SEC North: Ohio State, Michigan State, Wisconsin, Kentucky, Tennessee
SEC Central: LSU, Arkansas, Ole Miss, Mississippi State, Vanderbilt
SEC South: Florida, Georgia, South Carolina, Bama, Auburn
What's left of the Big Ten would join up with the Big 12 except Rutgers. Rutgers has no value without Fox forcing Big Ten Network onto NY-area cable systems by bundling it with YES. They would opt for SDSU instead. Upgrades the product more and gives the West a 6th team.
Their new 24-teamer...
Big 12 West: Arizona, Arizona State, Utah, BYU, Colorado, San Diego State
Big 12 Central: Oklahoma State, Kansas, Kansas State, Iowa, Iowa State, Minnesota
Big 12 South: Baylor, Houston, Texas Tech, TCU, SMU, UCF
Big 12 Midwest: Illinois, Northwestern, Indiana, Purdue, Cincinnati, WVU
UCF is stuck in with the Texas schools, but direct travel between Orlando and any of the Texas campuses isn't too bad.