I think you have nothing to lose if you want to try to salvage it by pruning it back. Best time is as soon as the flowers fade. Prune back as much as you are comfortable with after cutting out the dead wood but I'm not sure that I'd prune it very low. You may not know until next spring if you're successful. I would also give it a small dose of an organic fertilizer for acid lovers (nothing with salts or high nutrient numbers) and mulch with about an inch of peat moss to make sure the soil is acidic enough for it. I would not recommend mulching on top of the peat moss with any wood mulch which could bring in disease/fungal organisms. I have pruned my rhodies (about 20 years old) and various azaleas and they do respond well to it.
