As long as we're dreaming of the Big12 grabbing Washington, Oregon, Stanford, and Arizona St. to get to 16 schools, let's go ahead and then add Gonzaga for basketball only (or for all sports - Olympic sports don't matter one way or another).
Big12 is already by far the best hoops conference in the country, and adding Gonzaga would make it even better. Travel used to make their location a non-starter, but if you have Washington and Oregon and Stanford and BYU in the conference (and WVU and UCF on the other coast), why not?
And yes, I know, no one cares about basketball in realignment.