Iowa State hosted three ranked conference opponents last year and had around 51k for all three games. That is 10k empty seats in a small- to medium-sized.
#13 Baylor 50,842
#12 Oklahoma 50,662
#19 WVU 51,365
I'd say that's very good considering ISU had a 1-3, 1-8, and 3-8 records, respectively, for those games. How many other schools would have that level of support for a team going nowhere?