Survival of modern roses of all classes, still depends on the rose.
Roses that have more china and tea in their lineage are less able to handle cold conditions of hard winters than those roses that have fewer of the china and tea rose genes in their make-up.
This is because the chinas and teas come from a climate where dormancy was not required to survive the cold conditions you have in your winters. The plants never had the need to go dormant to survive and never adapted to handle the cold conditions you experience. They also come from regions with a longer growing season. All these things come into play in the survival of a repeat blooming rose in the colder zones.
To create a rose with good repeat that can survive cold winters is really kind of a breeding miracle, but the gardener still has to do his/her part to help the roses survive. Even roses that are cold hardy may succumb in a particularly long or harsh winter in northern climate zones.
Like all things gardening ... it depends.
Smiles,
Lyn
