That route is all good highway and very pretty this time of year. The Astoria bridge over the Columbia River can get windy in the afternoons but still plenty wide...just go slow if you need to. You'll go over one mountain pass to get over the coast range on your way over to Kelso/Longview. Take in Long Beach WA for a short side trip. Very fun city-walk and the beach boardwalk is always nice. The town is very RV friendly with plenty of parking just one block east of the highway.
Have fun...safe travels.
2000 Dutch Star 3859 DP (Spartan)
Flat towing a 2005 Chrysler T&C
Canby, Oregon / Riceville, Tennessee