Based mostly on geography, rivalries, tradition , like-minded institutions, with one exception keeping schools in the same state in the same conference, keeping the current 68 power 4 schools and adding a few....so basically fan's conferences. without $$$ considerations.....
Big 16 (Formerly known as the Big 10)
--Pitt
--PSU
--OSU
--Cincy
--MSU
--Michigan
--ND
__IU
--Purdue
--Minnesota
--Wisconsin
--NW
--Illinois
--Missouri
--Iowa
--Iowa St.
So......16 teams, dumping RU, Maryland, Nebraska, and the Pac 4...adding Cincy, Pitt, Missouri, ND, ISU
ACC
--U Conn
--BC
--Syracuse
--Temple
--Rutgers
--Maryland
--W. Virginia
--NC
--NS State
--Wake
--Duke
--S. Carolina
--Clemson
--Virginia
--Virginia Tech
15.....Hate to force Temple on them. Maybe somebody else would be better....already too many NC schools to add App St or E. Carolina. Maybe Marshall? U Mass? Anyway, dropping FSU, Stan, Cal, SMU, GT, UL, , Miami, , ND, , Pitt, ; adding U Conn, Temple, RU, Maryland, WVU, and S. Carolina.
SEC
--GA
--GT
--Bama
--Auburn
--Ole Miss
--Miss St.
--Vandy
--TN
--UK
--UL
--LSU
--Miami
--Florida
_-FSU
--USF
--UCF
16 teams....Florida-heavy, but that's within the rules. Dropping Arkansas, TX, A&M, Missouri, Oklahoma & S. Carolina. Picking up GT, UL, Miami, FSU, USF, UCF.....USF & UCF both schools with 50000+ students.
The Plains (Formerly the Big 12)
--Colorado
--Colorado St.
--Nebraska
--Kansas
--Kansas St.
--Arkansas
--BYU
--OK
--OK St
--TX
--TX A& M
--Houston
--TCU
--TX Tech
--SMU
--Baylor
16 teams...Texas and Texas North, but why not. I'm thinking Houston & SMU were on the outside looking in. The old Big 8 schools could never get along with the Texas schools, so add a couple more. Switching Nebraska for Iowa St to keep in-state schools together and for tighter geography.
The PAC 15
--Oregon
--OSU
--Washington
--Wash St.
--Utah
--Utah St.
--Boise St.
--UNLV
--Cal
--Stanford
--UCLA
--USC
--SD State
--AZ
--ASU
15 teams.....I violated one of my rules by putting BYU in the Big 12. Adding Utah St. (about 28000 students), SD State (37000), UNLV (31000) & Boise St (26000) to get to 15.
All-in-all I think you end up with 5 pretty competitive conferences with reasonable geography and most rivalries preserved.
EDIT: Adding Colorado St, a school with 34000 students and a great location, to the new Big 12.