First, force those schools in the three G5 conferences back to FCS. I'm fully on board with that.
Then create a division between the FCS and the. FBS for the other G5 conferences and those P5 schools like Wake Forest, Rutgers, Vandy, and the like who are very rarely competitive and don't have the same size fan base to pull their weight financially and have them join this new division.
Sure, for awhile, people will have their feelings hurt, but as time goes by and it is the new reality, they will get used to it, and probably be happy that they have their own championship to play for.