Speaking of Texas, one of the reasons I don't seem them in a Pac 16 is not enough partners in the Central Time Zone - here's how a PAC 18 addressed that:

PAC Plains - Texas, TT, TCU, OU, OSU, Kansas
PAC Pacific - USC, Arizona, Utah, Cal, Washington, Oregon
PAC Cascades - UCLA, ASU, Colorado, WSU, Oregon State

Give each school two permaent rivals in the other divison:

Texas, Stanford, Cal
OU, Southern Cal, UCLA
TCU, WSU, Washington
Kansas, Utah, Colorado
Ok State, Oregon State, Oregon
TT, Arizona, Arizona State

So Texas for example always has Oklahoma, TCU, Kansas, Ok State, and Texas Tech, plus Stanford and Cal. That's five central time zone games and the other four are split home and home - essentially just three trips to the West Coast a season. Cal and Southern Cal, and Stanford and UCLA would need to schedule outside the conference regime to meet more once every five years - a big downside but you can't get votes from WSU, Washington, Oregon, and OSU without them having at least two games with California teams.

Most every year Oklahoma, Texas, or perhaps TCU will host a playoff game. USC, Oregon, Washington, Stanford on the other side.

They could play the championship game not at the stadium of the highest seed, but in the new NFL stadium in Vegas, where it's easy to fly in on a moments notice.

Is this likely to happen - no.

But I really thing divisions of three are more workable than four pods and will give more satisfaction be that at 12, 15, or 18 schools.