Maybe, maybe not. Well established plants in the wild are frequently cut back like this. However, this will place a heavy stress on the plant and there is a possibility you will loose it.. If you cut the woody part back to about half the height you want the plant, but leave at least some green leaves, then the plant will sprout new growth from the woody part. When that has established itself, then you can remove all the old growth above the height you want. This less drastic approach will have a higher success rate.

Here is a link that might be useful: How to care for rhododendrons

For one anecdote, I pruned one rhody I had back to a stub because I hated how leggy it had gotten. It took a couple of years, but it's back now, looking exactly how I want it too.