When it is all said and done, I think the B1G will get Oregon, Notre Dame, Stanford, and Washington via expansion.
SEC is done until the ACC contract ends.
I think Notre Dame is eventually going to make the move, too much money and losing matchup with USC (along with possibly Michigan, Michigan State, Purdue, etc.) will be too much for them.
Controversial Take on here about Notre Dame, I do think Notre Dame's viewership is on a steady decline. It is still top 10 in the nation but Notre Dame was pretty much the leader of CFB up until 2000 and no one really thinks of Notre Dame as the King anymore (even 1990s saw them decline but they still had a reputation. I don't think Notre Dame has been Notre Dame since the Lou Holtz era).
Notre Dame has been surpassed by programs like Alabama, Ohio State, Oklahoma, Texas, etc. in perception.
Notre Dame is still a big pickup for the B1G but I think, long-term, programs like Michigan, Ohio State, and USC have greater staying power.