I would head inland on Hwy 20 from Fort Bragg to Willits and then North on Highway 101. I have driven the stretch from Fort Bragg to Leggett many times in a car, in a truck towing a TT and in a 30' motorhome. No way would I attempt it in a 40' with a toad. If you do decide to go that route, allow at least two hours to travel approximately 45 miles. You'll spend a lot of time pulled over to let other vehicles pass. It will be a very unenjoyable drive for the person driving.