Do you ever see in any reblooming irises in your part of the country?
I think Karl and Carol Jensen's irises ['Belvi Queen', 'Belvi Cloud' and others] might stand a decent chance of reblooming in your zone 5 Nebraska, since they were bred in Belvidere Illinois and rebloomed up there. I just got a rhizome of each of those two Belvi's from C&T Iris Patch late in 2015. If they increase, I can send you pieces if you still have a place where you could put them. Maybe the two season bloom would be more of an incentive for people to grow them there.
Best wishes, Tom