I would just let them leaf back out. You don't want to reduce the stems as you would lose leaves. Try to get a fungicide on your plant to protect the new growth as it comes out. Because it is under stress don't feed it now.

Defoliated plants use much less water and nutrients. Be sure the soil stays moist, but wait until they leaf out before fertilizing.

If these are established plants with good root and cane mass, I would consider pruning the upright growers, which will tend make all their new growth at the top over bare legs. The idea is to force new growth closer to the ground. That wouldn't apply to WS2000 and other arching plants.

Thank you both for the responses. It's very helpful.

It may be a worthwhile to closely inspect the canes now that you can see them clearly :-). If there are good canes remaining, it is a good idea to remove non-productive canes--these are typically old, diseased, or damaged canes that did not flower vigorously.

I strongly recommend that you don't trim. I can't find the threads which talk about strength, energy, food, etc. stored in the canes, but it is true.
Zone 4/5 is challenging enough for roses due to the short growing season. I would not weaken their defenses by pruning.

I would leave what ever cane and leaves you have left alone so they can provide some food for the plants.

Thanks to everyone for your responses. This has been a really unusual weather year. Because of the mild winter, my roses didn't lose any cane over the winter and were just loaded with blooms. Now with this new problem, I'm just not used to this sequence of events.

Roses defoliate here; I don't prune them back, but do deadhead them.

I rake in dry organic fertilizers in the summer months, and water with liquid organic fertilizers using a watering can for a soil drench.

Cooler weather and rain will help to bring on new leaves.

Skillful pruning can prevent black spot by improving air circulation and allowing the leaves to dry off before the spores have time to germinate (six hours) Rose midge can increase the chance of disease by creating dense clusters of leaves--it is often a good idea to cut that off.

The best defense against animals is a fence. Rabbits will do massive damage to roses if given a chance. 2nd best defense is fox or coyote urine.

I can see new growth coming on the worst-hit roses, and I finally managed to repel the woodchucks and rabbits with Plantskyyd. I chose that because I had read here that it stunk to high heaven but worked. Well, boy, it is the most repulsive thing I've ever come across in gardening, and that includes cups of dead japanese beetles, but it works like a charm. Thanks goodness for the generosity of GardenWeb gardeners in sharing their wisdom!