Personally I think Expand to 14.
First, top 8 conference champions.
#1/#2 -They have earned a Bye week each.
Conference champions ranked #3 - #8 Each have earned a round 1 home game. This will let the G5 conference champions get a chance to host the P5 schools in their stadiums, which is awesome for the little guy.
At-Large #1-#6, They will need to earn their way into the Top 8 playing away games. #1 will play the #8 conference champion, #2 Atlarge vs #7 Conference Champion, etc.
I like this because this will get the AAC, MWC, and SBC champions a home game against a Top 10 caliber team each year, This will also serve as a constant measuring stick between a Top league Conference runner-up vs G5 champion. (This is needed information annually for better or for worse.)
Then you continue with the NY6 bowls and National Championship game rotation for the rest of the playoffs.
If you want, you can create a 16 team playoff without byes.