This rose has come through two winters in Zone 3b to the tips. I think it could be rated as hardy to at least Zone 4 if not Zone 3. Edit spring 2019: another spring after a tough winter (about -35 F) and it is leafing out to the very very tips. I got this one from Forest Farm. As always, I worry that there might be some ID issues. I think perhaps the most defining characteristic would be the drooping, bottle-shaped hips and I can't remember if this plant's look like that. Will check this summer.