adding 2 schools to the SEC would actually help scheduling, they either go nine games if keeping an East/West split, or, if bylaws allow, setting up a four-pod system with 4 teams each. if, say for instance, VT and NCSU joined, for sake of experiment, you'd have:
SEC North: UK, UT, Vandy, VT
SEC East: Florida, UGa, NCSU, SC
SEC South: Bama, Aub, Ole Miss, MSU
SEC West: Arky, LSU, Mizzou, TAMU
play all 3 of your pod opponents every year, all 4 of one of the other 3 pods per year, and one team from each of the other 2 pods. so yeah 9 games, and guaranteed to go no more than 3 years without seeing any league school.
only question with this would be if NCAA would allow pods and further, if they'd allow a semifinal and final two week conference championship system involving all four pod winners or if it'd still have to be just a final game with the top two pod winners per computer rankings etc