I'm kind of amazed that the Pac 12 hasn't gobbled up Texas Tech yet, it seems so obvious to me that they need to extend a tentacle into Texas, and that west Texas would be the ideal place for them to do it.
Of course there isn't really an obvious candidate to pair them with. New Mexico would be a geographic bridge, but they are hilariously bad. Boise and UNLV have the markets, but not the "Academics" (or in UNLV's case, the football). BYU and Baylor are obviously out on religious grounds, and I can't even entertain the idea of OSUs 2&3 being in the same conference as one another, even if they are in alternate divisions. Hawaii would be kind of cool, but there are probably a myriad of issues there as well.