I wish people would stop thinking that geography for divisions matters. Yes it makes sense from a fans perspective but it doesn't from the institutions and TV perspective, and that is what matters here. TV wants competitive teams on the field, with competitive balance between divisions. They don't want, a Big 12 North and South where the South dominates the North, except for on rare occasions.
Institutions don't care about geography other than to make sure they have access to quality recruiting ground. So for ISU, KU, KSU, and WVU it is important for these athletic departments to protect that interest. So a North South split isn't going to work. Geography isn't going to matter. Competitive balance and access to recruiting hot beds is going to matter.
As an ISU fan, this will suck from the stand point that it most away games are not going to be driving distance from Ames. But from a competitive stand point it is important to us, because it gives ISU a chance to recruit more effectively and put a better product on the field. Kids want the chance to play in their home state as often as possible so it is very important that the conference allow the teams to play in TX and if the speculation is true the south (FL, GA, SC) as much as possible and the only way to insure that is to forget geographic divisions.