Here are some western population statistics with the national rank for our geographic footprint:
Total Population
#1 California
#13 Washington
#14 Arizona
#21 Colorado
#27 Oregon
#30 Utah
#32 Nevada (recently passed Kansas, Mississippi and Arkansas; about to pass Iowa)
#36 New Mexico (bigger than Nebraska and West Virginia)
#39 Idaho (still a bit smaller than West Virginia & would be smallest state with an FBS program; close to passing WV, NE and NM)
% Increase (2010-2018)
#1 Utah - 14.4%
#4 Colorado - 13.2%
#6 Nevada - 12.4%
#7 Arizona - 12.2%
#8 Washington - 12.1%
#9 Idaho - 11.9%
#11 Oregon - 9.4%
#19 California - 6.2%
#38 New Mexico - 1.8%
When I look at this, I see real value in adding Nevada and possibly Idaho to complete our footprint with a Pac-14.
I see the absolute most value with a Pac-16 that adds UNLV, Oklahoma, Texas and Texas Tech.
Texas: #2 population / #2 population growth rate
Oklahoma: #28 population / #23 population growth rate
And if we couldn't get OU and UT, I'd be very much in favor of Boise State, New Mexico and San Diego State instead. (San Diego is the 17th largest metro in the US - I'd take them if we couldn't at least poach TTU from a Big 12 breakup. Also, TTU could make UNM superfluous and replace them with SDSU added.)
That looks like a true regional conference that dominates the west to me. My strong preference is getting something into Texas. TTU is the clearest relationship due to it being the only TX FBS west of the I-35 corridor and it having been in a conference with UA, ASU and UNM from 1932-1956 (Border Conference) and with CU from 1996-2011 (Big 12). There's a cultural affiliation and a history there.
So I guess where I land is that while OU and UT are the ultimate prizes in the next round of realignment, I'd be very happy with a Pac-16 that added Boise State, UNLV, New Mexico/or SDSU and Texas Tech. On the surface that may not look exciting since it lacks big name programs that obviously move the needle. But I believe that it creates true regional excitement and makes a ton of sense.
And I wouldn't be opposed to expansion to 16 through a regional rivalry model the Pac-8 and Pac-10 were based upon: adding CSU and either BYU or Utah State for 14; TTU and UNM could make 16 -- or UNLV plus either Nevada or SDSU could also make 16.
https://simple.wikipedia.org/wiki/List_of_U.S._states_by_population
https://en.wikipedia.org/wiki/List_of_metropolitan_statistical_areas