I see that this is an old query but I also grow Destined to See in a cold zone (4b) and have grown it for many years. See my photos under celestialrose. My clump is enormous and grows in a border by the roadside and I do not winter protect at all. I live at an elevation which has quite a bit of wind and snow and yet it never suffers any dieback, is vigorous and blooms very profusely. It's one of my best bloomers.
