Welcome to NGA,
@Dantra1 !
I'm not an expert on rhododendrons by any means, although I do have a couple of them... but I'm pretty sure you shouldn't cut them back in the fall because they make next year's flower buds pretty much right after they flower during the current year. In other words, you won't get any flowers in the spring if you trim them now.
I hope someone more knowledgeable will also answer your question.
