As one of the other posters indicated, you have to do Neah Bay and do the short hike to Cape Flattery. It's the most northwestern point in the 48 states. We stayed at the Hobuck Beach Resort with our 32' Class A. There are plenty of spots open as Neah Bay is pretty remote and off the beaten trail. But, don't expect resort level accomodations. Most of the people that were near us were long term residents (mainly fisherman). Nonetheless, it's right on the beach and we truly enjoyed the area.
On the western side of OP, I would recommend a couple places to stay, Kalaloch and Quinalt Rain Forest. Kalaloch is right on the Pacific Ocean and is popular and most spots don't have sewer. Quinalt RF is private run and has hookups but no sewer. Both of these have a ton of hiking trail heads nearby.
On the northern side of OP, Sol Duc RV Resort is nice as you can use the hotel accommodations when staying in the RV spots. THe hike to Sol Duc hot springs is easy and a must.
Before you leave the peninsula, there is a state campground called Fort Worden in Port Townsend. We stay here every Memorial Day weekend.