Growing Rhododendrons on the Prairies

I have a two Rhododendrons - Nova Zembla, and a Helsinki hybrid. I've had each for many years. I haven't really done much with them, except try to protect them in the winter. They are not dead, which is good, but they haven't really grown, either. The Nova Zembla has actually shrunk, because of snow load and ice. Both are planted in part shade, but do get quite a bit of sun. Neither has ever bloomed. Should I move them? What is the best fertilizer to use, and how much and when should I apply it? I can see new buds on them now, like every year, but how do I know if they are leaves or flower buds? The Helsinki is at the edge of a raised bed, so gets very good drainage, and the Nova Zembla is on a slight slope. I also have one more that is still in a pot, but don't know where to put it. My zone is 2b. Any advice?

 

Probably the flower buds are dying in winter cold that kills these but not the rest of the plant.

 

But, where are the flower buds? I see buds, but what are they?