If it is, I think you have a decent shot at winning the bet. Too much uncertainty, though, if it includes postseason.
A quick glance at Iowa's schedule, I can see a good shot at 20 wins — that's with Iowa beating ISU head-to-head. I might set over-under at 19.
If you think ISU can do better than that (and I think it will happen), you're OK.
Why not just do the game itself?