Could go to a system like the NFL with more than 2 divisions. Could do 4 divisions of 5 pretty easy with 20 teams. The only thing would be that there isn't as much parity as the NFL (the best and worst NFL teams are ridiculously close in talent) so you'd have to be pretty careful how you divided it up.
Don't you have to just go geographical and live with the imbalance?
Aside from the blue bloods, the other programs wax and wane (the blue bloods can struggle too, just to a lesser extent and for shorter periods of time). What ever plan you have to achieve parity could look like an abject failure in 2 years. So do you just plan to keep shuffling every few years, or do you embrace the map and traditional rivals? I think those regional rivalries matter a lot in college FB, and if you lose those, you lose a huge part of what people love.