I agree that it won't be easy. But he is making a lot of assumptions though, especially regarding the amounts. I suspect he's getting his numbers from the ACC who wants to make it look as bad as possible (and I'm sure it is bad).
First, I believe the GOR is per use with the agreement with espn. If that agreement with espn goes away or is voided, I don't believe the acc can enforce it. The question becomes why would espn do this. The only reason would be if wspn can make more money with the SEC and dissolving the acc network. Personally, I don't believe the acc network, even with its favorable deal, is making espn a whole lot.
Second, he doesn't believe 8 teams can leave the acc. The big 10 and sec can easily take 5 to 6 teams from the acc - miami, Clemson, fsu, NC, ncstate, uva, Duke, are all potential candidates for those conferences. The remaining teams, plus Pitt, VT, Louisville, etc would probably fair better, and get a better deal, if they leave to whatever the new pac12/big 12 conference will be. Without an acc, the acc cannot enforce the agreement. This would likely be the easiest and cheapest scenario