101 south through Oregon is a wonderful trip. You'll have no problem with a 28' Class C and a toad. We've done all or part of it in a 37 and a 40 footer with toad.
There are only a few steep grades, and those are very short. There are a few curvy sections but nothing to worry about. Scenery most of the way is beautiful and if you're like us it will take you all day to travel 100 miles between stopping at scenic viewpoints, interesting little shops and restaurants, walking on the beach. Etc.
Regarding the Redwoods, you may want to keep going south after Crescent City. 101 passes through Redwoods State Park, Redwoods National Park, and Humbolt Redwoods Park.
Happy Travels!