Still think you make it 8. 5 p5 teams that win their conference championship, 2 at large, and 1 non power5 guarantee.
G5 guarantee contingent upon top two rated G5 square off on championship weekend. Conference champions and G5 winner get top 6 seeds.
You essentially get a 12+2 team playoff of the 2 top teams from all power 5, top 2 G5, and remaining top computer rated +2 after the dust settles on conference championship weekend.
This preserves the importance of conference play and provides incentive to build good schedules out of conference. G5 teams have a legitimate test before entering playoff with the benefit of not being one of the bottom 2 seeds. I think any team that back doors its way in without winning a conference championship should face the top seeds the first weekend.
This maintains the importance of the season, puts some more value on the CCGs, gives best G5 an opportunity beyond being perennial cannon fodder as the last team in, still provides a direct benefit to two of the best P5 teams who come up short in the CCG, and resolves itself in 3 weeks of games after the end of the season.
I'd have two regionals which would host the first two weekends of games and the championship game would be at a third location.