We live in Tucson area - this is our 5th trip to OR Coast...4th in 5th wheel. We are currently in Cannon Beach and will again stop in Newport and Bandon. Have also stayed in Winchester Bay a couple of times.
Would suggest you wait until August as the rainy season usually ends around the end of July.
Cannon Beach RV Park has always been our favorite and we have been up and down the whole Coast. Lots of trees and grass; need reservations way in advance. PM or email me on this one if you are interested. Interesting town and area. Love Ecola State Park.
Winchester Bay is a beautiful but not much to do in area unless you ride dune buggies in the sand.
Newport and Bandon best bets for crabbing I think; would suggest Bandon if one had to choose. Lots of crabbing there (don't mean my wife!). We will be at Bandon By The Sea RV Park for 8 days early Sept.
Again, feel free to email or PM me.
We love this area - obviously.