101 northern Ca.

199 is a very good road ,lots of truck and rv traffic with a few tight turns but nothing to worry about.
101 is a major north south highway with a few hills but most have passing lanes if they aren't already four lane. again no concerns with your rig
klamath river rv park is a nice park right on the water and only blocks to the ocean

US Hwy 101 from Cummings to Redway has some slow spots but it's a wonderful drive. Your size is fine. I'd suggest being prepared not to stop in Garberville. Last time I went through at least 200 homeless men were all over the town. Very unfortunate.

Haven't been on Oregon 199 recently.

Actually, Benbow Valley KOA RV park outside of Garberville is really lovely. Used to be a private resort, then became a KOA, but there is still a high class restaurant at Benbow Valley Inn, and an adjacent golf course giving the KOA privelages.

199 from California state line to Crescent City is only about 40 miles or less.........good road! From about Hiouchi to Crescent City you have a few slow corners but bit rig use it all the time.