My idea would be to reduce the number of FBS teams from 130 down to 96. That would give you 8 regional conferences with 12 teams each, and there wouldn't be a separation of P5 and G5 conferences. Then have a playoff with all 8 conference champions.

FBS Division:

PACIFIC
Hawaii
Fresno State
San Diego State
UCLA
USC
Cal
Stanford
Oregon State
Oregon
Washington
Washington State
Boise State

MOUNTAIN
Nevada
UNLV
BYU
Utah
Arizona State
Arizona
New Mexico
Colorado
Colorado State
Air Force
Wyoming
Nebraska

SOUTHWEST
Texas Tech
North Texas
SMU
TCU
Baylor
Rice
Houston
Texas A&M
Texas
Oklahoma
Oklahoma State
Tulsa

SOUTHEAST
Arkansas
Arkansas State
Tulane
Louisiana Tech
LSU
Mississippi State
Mississippi
Auburn
Alabama
Tennessee
Vanderbilt
Memphis

ATLANTIC
Central Florida
Florida
Florida State
Miami
Georgia
Georgia Tech
Clemson
South Carolina
NC State
North Carolina
Duke
Wake Forest

CENTRAL
Kansas State
Kansas
Missouri
Iowa State
Iowa
Minnesota
Wisconsin
Illinois
Northwestern
Notre Dame
Purdue
Indiana

MIDWEST
Michigan
Michigan State
Central Michigan
Western Michigan
Toledo
Ohio
Ohio State
Cincinnati
Marshall
West Virginia
Louisville
Kentucky

BIG EAST
Virginia Tech
Virginia
Penn State
Pitt
Temple
Rutgers
Maryland
Army
Navy
Syracuse
U Conn
Boston College
.............................

Then have the exact same format for the FCS Division:

WAC
San Diego
San Jose State
Sacramento State
UC Davis
Cal Poly
Azusa Pacific
Weber State
Utah State
Southern Utah
Northern Colorado
Northern Arizona
New Mexico State

BIG SKY
Eastern Washington
Portland State
Idaho
Idaho State
Montana
Montana State
North Dakota
North Dakota State
South Dakota
South Dakota State
Northern Iowa
Drake

MISSOURI VALLEY
Southeast Missouri State
Missouri State
Illinois State
Northern Illinois
Southern Illinois
Western Illinois
Eastern Illinois
East Tennessee State
Tennessee State
Tennessee Tech
Middle Tennessee
Chattanooga

MID AMERICAN
Indiana State
Valparaiso
Butler
Ball State
Eastern Michigan
Akron
Miami OH
Bowling Green
Kent
Youngstown State
Eastern Kentucky
Western Kentucky

SUN BELT
UTEP
UTSA
Texas State
Louisiana Lafayette
Louisiana Monroe
Southern Mississippi
South Alabama
UAB
Troy
South Florida
Florida Atlantic
Florida International

CONFERENCE USA
Georgia Southern
Georgia State
South Carolina State
East Carolina
Coastal Carolina
Appalachian State
Charlotte
Richmond
William & Mary
James Madison
Old Dominion
Liberty

IVY
Harvard
Yale
Princeton
Columbia
Cornell
Dartmouth
Penn
Brown
Lehigh
Lafayette
Bucknell
Holy Cross

AAC
Villanova
Georgetown
Buffalo
Albany
Stony Brook
Central Connecticut
Delaware State
Delaware
Rhode Island
U Mass
New Hampshire
Maine