Assuming only football matters...
Here are the ACC / B12 / Pac12 teams with lower ratings in 2021 than Colorado (#64 366k), : Duke (64k), Boston College (156k), Syracuse (219k), Cal (222k), Houston (232k), Oregon State (321k), Arizona 337k
Here are the ACC / B12 / Pac12 teams with less than 1M average viewers despite significantly better years than Colorado (bowl game or better): UCF (407k), Washington State (483k), NC State (525k), Wake Forest (526k), Pittsburgh (550k), Virginia (611k), Louisville (616k), K State (636k), Texas Tech (798k), Utah (994k)
So just by the numbers it's close since that's 17 schools, and you also have to consider market overlap / desirability (e.g., it's hard for me to believe that NCSU won't rank as a top priority for whatever of the two doesn't land UNC), comparability of TV deals that enable those ratings (e.g., UCF would have much higher ratings in a power conference),and administrative support that makes it likely to grow interest in the program.
The schools that you listed that aren't above:
- Cincinatti (1.26M) - an outlier year, would want to see how they did a couple of years ago in the ratings, but still clearly have admin support and are in a big market, academics and market overlap would be an issue for the Big Ten
- Iowa State (1.29M) - likely a take before CU, only argument is sheer size of market and general population growth trends
- TCU (907k) - if Big Ten can get comfortable with the academics, most likely a take before CU, probably not true of the SEC given the existing Texas footprint
- KU (540k) - I mean this one shocked me - but the numbers are what they are. Most likely a take before CU
- WVU (948k) - similar argument as with Iowa State
Finally, SEC and Big Ten schools that have fewer viewers than Colorado:
- Vanderbilt (37k)
Uh, yeah, that's it.
Another takeaway - as a Wake alum - Wake should not be at the head of these lists as the primary example of program that doesn't deserve to be in a power conference.It is a well run program with lots of booster investment and that stands for something - with many more viewers than many much larger schools.