some things which are factors when deciding a base
hangars available for on-site maintenance, to include jacking plane and tire, engine changes
number of hotel/overnights in that city (base status reduces this cost)
local economy, potential
gates, jetbridges, costs associated with the local airport board/committee/authority
other airlines operating there = not revinventing the wheel, a pool of passengers to steal from, etc.
that said, my crystal ball says CVG
https://www.wkyc.com/article/news/lo...s/95-479010736
https://www.cvgairport.com/about
Pre-Covid article but still good:
http://www.usmayors.org/wp-content/u...-July-2018.pdf
Remember Frontier's passenger demographic is not really "brand loyal" they are "cheap loyal" so the more to steal from other carriers, the better. Business 101. McDonalds does it with Burger King (this is why a McDonalds is one block away from a Burger King). Also, big Fortune 500 HQ hub cities typically have employees with families and kids, and some income to travel. Again, Cincinnati.
My crystal ball....