I read that if over 50% of the schools leave the ACC en masse, the Grant thing is moot, dead.
Therefore, do it. Basically majority leave, then reform the ACC. Clemson and others if they have options they can excercise that option. As for the P12 schools, they can perhaps try to reform the P12, or, just become Independents. I am sure they could put together a fine Schedule. ND has been doing it forever.
The ACC would still exist even with a majority of schools leaving. Each exiting school would need to pay the $120 million exit. Clemson and a few others could probably find a better landing spot in the SEC or B1G. Others won't and will end up with a worse TV deal on top of having to pay the exit fee.