Suppose the B12 dissolves because it can't form a network with only Texas as a major cable market, and the ACCN can't get off the ground with only North Carolina, Virginia, and maybe Florida as markets. With TV agreements expiring at the same time, they might consider a re-arrangement in which the schools that bring major cable markets regroup and leave behind those that don't.
What about this league:
Texas, Oklahoma, Kansas, Iowa State, Florida State, Georgia Tech, Clemson, UNC, NC State, Duke, Va Tech, Virginia, UConn (13 teams) + Notre Dame with an indy/ACC-like deal would be a good nucleus and they'd have a number of other schools to consider for 3 more to get to 16. You could get a network out of that.
I suppose you'd lose some (maybe SEC takes NC State and Va Tech to have penetration throughout the southeast; maybe B1G picks off a few - Kansas and UConn?). But you'd still get a conference network out of the best of the B12 and ACC.