I garden in the Yukon. I do grow mini-roses in pots. I have successfully overwintered about 20 for a few winters by bringing them indoors once it turns cold enough to freeze soil. Once the leaves have fallen or are brown and dormancy is approaching I cover the pots with blankets and keep them as close to zero as possible until we get 6 hours daylight again.Roses need sunshine so our low light does not allow them to thrive.I keep the pots moist.I know your conditions are different to mine but this might help?
