ND is making approx 11 million per year from NBC. So those numbers are easily dwarfed by what they'd make in the B1G. I'd be surprised if ND alums were coming around to being a non-indy in anything except the worse case scenario. The outcry last summer/fall against a move to a conference was HUGE. Now, if you start talking super-conferences I'm guessing the rational portion of the fanbase gets smart. But an imploding Big East doesn't force a super-conference era. Conferences like the Big 12, ACC, and SEC have to take the remaining Big East football schools on for that to happen. UConn and WVU want out now I'm sure...but that doesn't mean it'll happen.
Any way you slice it, if ND still values independence first then only the superconference era means that the Big East (however it is constituted) won't be able to serve as a viable home for the Domers.