We usually do Klamath Falls to Winchester Bay (we love that place) once or twice a year. We take 140 out of Klamath to Central Point then I-5 north to Sutherlin then 138 then 38 over to the coast and then to Winchester Bay.
We are a 33 foot Vacationer towing a Jeep Wrangler. It is a good route, about a 5 hour drive or so, maybe a tad less.
2016 Holiday Rambler Vacationer 33C towing 2008 Jeep Wrangler Rubicon 2dr 6spd manual.