Spindly Rhododendrons?

Last year in early April, we bought a large ranch style home in the countryside outside Molalla in Oregon. It has 40 acres and the area around the house is wooded. We have a horseshoe drive in front of the house which is lined with very old large beautiful rhodies (rhododendrons).

This year (with nothing being done to them last year.) their blooms were much later with very spindly branches and the small leaf rhodies, none at all. The small leaf ones have a leaf blight of some kind. The two spindly one are alone in the yard separate. The ones in the drive kind of all run together. I have no way to send a photo. Please HELP! What do I do to save my once lovely drive?

Hardiness Zone: 8b