He’s not going to retire. Iowa is famous for electing politicians that have served past their sell-date. Terry Branstad has been Governor since 1983.
And if Iowa has a rat Gov. when Senator Grassley croaks? There’s another Grassley in the statehouse. Same name but the stench of dynasty.
Kim Reynolds has been the Governor of Iowa, since 2017.
Branstad does hold the record for having served longest as a Governor, but it was from 83-99 then again from 11-17. There were two Democrat governors in the interim.