GF and I did a trip all the way down the coast from Astoria to Florence, as mentioned in the thread linked above there are tons of campsites
along the coast (at least) and lots to do in many of the ocean side cities/towns. Rent a Yurt? The drive is incredible, if you're on the coast allow yourself extra time to stop a points of interest and what not as there's tons of things to see along the way. We did the trip in a little less than two weeks and certainly didn't have close to enough time to see everything that we wanted to. Also I would highly recommend taking a ride on the dunes with one of the sand-rail companies in somewhere like Florence or Due City. BEST $25 dollars I've spent on entertainment in a long time. I'd also recommend you stop at the outlet mall in Woodburn, Oregon just south of Portland on the I5. No tax = win.
Little VW vs. Dune Action: