K-State would likely play independent before accepting a demotion.If the SEC and ACC merge, it will be when all power 5 conferences merge to create the "new NCAA" which will be 80 teams. They'll probably re-create or re-imagine conferences at that point.
My theory (I will try to put this in sequence):
- The Big 12 will dissolve (thus taking us from power 5 to power 4)
- The remaining Big 12 teams will be re-distributed across the Big Ten, PAC 12, AAC & ACC
- Baylor/TCU/Texas Tech/OSU to Pac 12 (16 total)
- Iowa State to Big Ten (15 total)
- WVU to ACC (15 total)
- Notre Dame finally joins the ACC in football (16 total)
- Kansas/K-State to AAC (13 total)
- Boise State joins AAC (14 total)
- Big Ten finds a 16th team
- AAC finds a couple more Group of 5 teams to round out their conf at 16 teams (FAU? WKU? Air Force? UAB? North Texas? BYU?)
- AAC becomes the 5th "Power 5" school
- This persists for 5 years or so then a new org of the 80 power 5 schools is created.
KU would more than likely be your 16th Big 10 team.