Here's a full picture of it

The canes still look green. Try potting it up and see if it recovers. You'll need to keep it moist but not soggy and don't fertilize it until you see new leaves forming. In your cold zone it may not get any new growth now until next spring. Keep it very well protected for winter and see what happens.

The white stuff looks like some sort of insect infestation causing a variety bark scale, which can be scrubbed off, and the winter should take care of it shortly. I'm new to roses, but I've seen it on other shrubs like crape myrtles and azaleas.