I can't see any possibility that Carolina leaves the ACC. Even at basketball schools, apparently football still makes the most money, but I can't see them bolting one of if not the premier basketball league for a football conference.
They wouldn't give up the conference games against the Tobacco Road schools. They would still play them, but winning the ACC over Duke is equally as important as national championships.
The NC Legislature as stepped in on stuff like this in the past. After a couple of brawls between NC State and East Carolina, the two wanted to stop playing. The state legislature passed a measure that said yes you will.