I don't think you're understanding the situation. It isn't an either/or. As long as there are 9 Big Ten games, Iowa cannot chop off the non-Power 5 games while also continuing to play Iowa State.
They have to play two buy games against FCS, Sun Belt, MAC every year.
If they push ISU off the schedule, they would still play two buy games, but they would also get to play OTHER P5 schools.
Basically, each Big Ten team that requires 7 home games is in this boat (Minnesota included). You play the road P5 non-conference game when you have five B1G home games, and host the non-conference P5 game when you play four B1G home games. Minnesota gets to vary it from year to year. Iowa doesn't get that option. It has been Iowa State every year.
So, while Minnesota gets home-home with Oregon State, Colorado, Mississippi State, Fresno State, Colorado State, BYU, North Carolina, TCU, UNLV, USC, Cal, etc.
Iowa gets home-home with Iowa State, Iowa State, Iowa State, Iowa State, Iowa State, Iowa State, Iowa State, Iowa State, Iowa State, Iowa State, Iowa State and Iowa State.
See how that would get old? Plus it is a lack of national exposure. I'm glad we get to travel to new places every couple of years.