The coast drive I took was mostly south of Portland, not north. The Oregon coast is a beautiful place, but Washington has a less interesting coastline, from what I heard and saw. The area around Astoria, Cannon Beach, and Seaside is beautiful, and we enjoyed spending about 3 days total in that area just hanging out at the beach. This is Cannon Beach.
There are a ton of motels and hotels along the coast, but they tend to book up on the weekends.