I'd almost say look for the Big 12 to do an ACC type of thing. Somewhat non-geographical divisions with cross-divisional protected partners (something that, as mentioned, the SEC also does, Big 10+2 too).
We'd be put in OU and Okie Lite's division, with Texas, Tech and Baylor in the other. UT-OU, Tech-Okie Lite and TCU-Baylor would be the pairs. Split either KU and Mizzou or KU and K-State but match them across the divisions. Iowa State gets the other Big 12 north team as a cross-division rivalry. And then do that with whatever your other two teams are, say Louisville and West Virginia.
I don't think it'd be ideal for us because it gives Texas and Tech a way to duck us many years, but whatever. I think it makes the most sense from a competitive balance standpoint.
Possible divisions:
West-East (for lack of a better name):
Baylor-TCU
Texas-OU
Tech-Okie Lite
KU-Mizzou
K State-Iowa State
Louisville-WVU
All that said, I bet they stick with 10 for a while longer.