I had a tough time finding any recent numbers, but here is the best link I could find:
https://thequad.blogs.nytimes.com/2011/09/19/the-geography-of-college-football-fans-and-realignment-chaos/
Here are some interesting numbers from the time of the article:
BYU: 709k
AAC Teams:
Uconn: 618k
USF: 520k
UCF: 506k
ECU: 348k
Cinci: 322k
Others:
Lville: 300k
Utah: 351k
Boise: 483k
USU: 65k
Toledo: 109k
TCU: 370k
USC: 1.2 mil
Texas 2.5 mil
Ohio St: 3.1
Wake F: 149k
Miss St: 550k
Basically, there are a number of AAC teams that in terms of fanbase could match up with mid range P5 schools. Houston and Memphis were very low in the article, but that has changed in the past 5 years, as has Utah and Lville I am sure. What the conference would be missing is that 1 marquee school. Some team with over a million would change the view of the conference in my opinion.