I think the GORs are a problem so we have to wait about 10 years. Although if anyone can break a GOR its Texas.
If Texas feels their status is threatened, they will dissolve the Big 12 before anyone can beat them to it by leaving. If OU and KU openly said they were in talks, Texas would fire back with likely the Texas 4 pack to the Pac 12.
Adding Texas, Notre Dame, Mizzou, OU, KU, and say Virginia would be a game changer towards realignment. Not only would the Big 12 be killed off, but the ACC would likely fold as well due to the SEC pillaging them. The Pac 12 would have to settle for the remnants of the Big 12 and we would be left with 3 super leagues.
I think the only interesting expansion that would happen in the near term (short of the Big 12 adding a couple teams), is if Texas decides to implode their conference.
I really hope the Big 10 doesn't go past 16 teams, but I guess if they added 6 more we would still play each other every 3 years. (home and home every 6). The Big10 would probably be going after 6 of the following teams (no order, although I think the top 6 are first): ND, Texas, Virginia, NC, OU, Kansas, GTech, Forida, Iowa St. Missou, Vandy, Duke, Texas A&M
I think FBS football could get to four 20 team super conferences. There are 64 in the current power 5, 4 independents, and if we consider Boise, Uconn, Cincy, other teams from Florida and Texas that have value in recruiting, plus a few other MWC teams like Air Force, SanDiego St and maybe Colorado St., we can get to 80. The ACC would probably end up being an odd looking conference geographically. It would be interesting to see who the last 6 to 8 teams are that get in and to watch the fight over the Texas teams.