How tall and wide are your Summer Sunshine (which is a zone 6 rose, by the way) and Gemini rose bushes? You've said many times that your roses don't grow to the expected average height and width. And you say Blue Girl "stayed mostly green all the way up the canes"? That's a pretty good sign that it wasn't hardy in your zone. It should have stayed all green all the way up the canes.
When we talk about the winter hardiness of roses, we mean the lowest zone in which the rose will grow to its full potential with no protection (not even an inch of mulch) in winter.
