We just made an 11 day loop to Newport, OR - north down the coast to Long Beach, WA for the International Kite Festival, then on to Ocean Shores, WA.
If worse comes to worse (as a rule) you can tuck in at a casino (free) for a night or two. If they have some big event happening the casino might charge you $15.00.
Casino Camping Map. It's often boon docking, but I like that the casinos have security cking their parking lots throughout the night. There were some huge rigs in the RV parking lot at Ocean Shores, WA. Plenty of room for Rvs of all sizes.
The Quinault Casino (Ocean Shores) even had a little shuttle coming out to run the RVers to/from the casino. We're not gamblers, but the food is always good and affordable.