Just beginning to research it, I see a lot of teams had a very strong regular season, only to lose their CCG and bowl game, sort of mulling their perceived strength. So I think regular-season conference record will be more meaningful than their final record. I'll look for teams with 3+ conf losses.
2015 we have a Utah team winning the PAC South at 6-3.
2017 Stanford went 9-5, with 2,000-yd rusher Bryce Love, but they allowed more total yards than they gained. That's pretty bad.
2018 Pitt won some division of the ACC with a 7-7 record. They got their asses beaten by Penn State, UCF, and Clemson. Also outgained in total yardages for the season.
We may have a winner! 2019 Miami went 4-4 and won their division. 6-7 overall, and here are their final 3 losses: FIU, Duke, and Louisiana Tech. Yeeesh.