Root rot often causes the leaves of rhododendrons to curl and die. It can spread to its neighbors, so I suggest you remove it. If you choose to replace it look for disease resistant varieties. Check with a good independent nursery in your area. It's important to keep plants watered during drought, but overwatering can cause fungal diseases. Be sure to clean you tools with alcohol when finished and clean up all leaves and twigs. Best and Happy Yardening, Nancy
Gabrielle, I am not a plant doctor so I don't feel qualified to make that call. You said removing the damaged material will leave behind a misshapen plant. One of the big mistakes we gardeners make is not letting a sick plant go. Three years later you may say - but it still has a few green leaves. Life is not easy --- Best Nancy