I am in zone 4 Montana and constantly push limits with zone 5 plants. I have had only a few others which also survived but didn't flower. I tried Oakleaf Hydrangea and had the same results - survived but didn't flower. I grow Viburnum carlesii which is usually listed as zone 5. It blooms beautifully. I have had it for 8 years.

If I had room for a Double File I would try it in a heartbeat because I have great success with Zone 5 plants. I think nurseries are conservative in their estimates regarding zones. If I see zone 5, I order. We can have some awful winters here - definitely Zone 4. I now indicate I am from zone 4b (warm zone 4) because I have had such good luck from nominally zone 5 plants. I would very definitely think you have a good chance Doublefile viburnum would survive in southwest Wisconsin which I would expect is significantly warmer than where I live.

Some of the "zone 5" plants I grow are Buddleiea, Clethra, Fothergilla and Hamamalis (Witch Hazel).

I hope you do try it. I'd love to find out if it works for you if you end up trying it out.

Thanks so much for the information. I do believe I'll try it. Most of our local landscape centers and nurseries cater to zone 4 or colder but I get to Chicago occasionally and I'm sure I could find one there since they are zone 5. I probably won't know until next spring at the earliest if it survives and possibly a few years longer if it will bloom. We are only about 30 miles into zone 4 and live in the middle of the woods which gives us a little additional protection so I think it's worth a try. The doublefiles are just so beautiful and I have a perfect spot for one that would be wider than tall.