The small start and end towns like this year are nice. Logistically though a short list of start & end towns that are bigger would help logistics since RAGBRAI is so large. Those towns might even develop some semi-permanent infrastructure to support RAGBRAI if they were in a small rotation.
Start towns big enough: Council Bluffs and Sioux City.
End towns big enough: Dubuque, Bettendorf/Davenport, and Burlington.
All have good transportation options (airport access, 1 way rental cars) and enough space for charter groups to stage in and out of.