A few thoughts for everyone about "Highway 1," "Coast 1," "SR-1," "PCH" or Pacific Coast Hwy., etc. - whether north of or south of San Francisco
- it's pretty much a winding 2 lane old school road dating from the earliest days of roads in the early 1900's (1920-30's mostly), which has been successively superseded by wider & more "comfortable" roads to travel on, with US 101, then I-5.
Of course it's been regraded, repaved & recontoured with guardrails added for safety since then, but it's still a small 2-laner - especially in the northern CA stretch mentioned above.
However, it is magnificent scenery - especially north of Morro Bay up through Big Sur, being the better known part - but with the stretch north of San Francisco being equally rewarding, as well as the Oregon coastline section, if a bit less mountainous.
For much of those two noted sections, you're on a road basically carved into the mountain sides where the mountains drop directly into the Pacific Ocean.
So I wouldn't necessarily take it completely off your "To Do" lists, but rather plan for it accordingly, & take your time.
So here are my thoughts & suggestions....
1.) If you're at all leery
about driving along a road hanging onto a mountainside, with a shear drop to the ocean next to it - then do the trip, leg or run of the SR-1 from South to North
- so that you're on the INLAND
side of the road next to the mountain, rather than next to the cliff. You can still see the views, but your stomach may be calmer there.
2.) As others have said, take your time, use a speed that you are comfortable with
given the road conditions & your rig or vehicle, & just let others pass, & do not get pressured by the impatient folks behind & whizzing past.
I've been one of those "whizzers" in past years in my `73 Porsche 914-2.0 sports car enjoying the "twisties" during off-season, & we types won't hold a grudge for the occasional trailer/RV touring folks, & most should know better than to try to enjoy that road's curves during peak season. But I've also been one in my `88 VW Westfalia with it's blazing 0-60 in 30 minutes, loaded down further with wife, kids & gear - at far more sedate pace! We've yet to do it with our `60 Avion T20 - it being relatively new to us since 2012, but we will.
3.) The section of SR-1 just across the bay from San Francisco which goes down to Stinson Beach etc. is limited to vehicles of a certain length - which I believe is only 22' if memory serves - so you'll need to cut over from US-101 a bit further north.
Also, while not length limited as far as I recall, the far northerly stretch up from the coast to US-101 which the OP mentions is also quite winding, so some folks may want to cut across on one of the easier roads to the south of the stretch up the valley, in favor of a less winding alternative a bit further south, & forego that last bit of the "PCH Experience."
4.) Make sure you have a properly set-up & dialed-in rig, then check ALL of your towing equipment & brakes, steering, etc. before that run, as well as during it at every stop. If in any are in doubt, then don't do it - or stop & get it repaired before continuing. this is no place to experiment nor take risks with a damaged sway control or coupler, etc.!
5.) Leave yourself enough time & then some more in order to do this run - take your time, enjoy the view, stop often to take it all in & see the various sites. Also, plan to eventually do both the north of SF & Redwoods area, as well as the CA Central Coast & Big Sur sections - eventually, even if on separate trips. So research & plan it all & map it out ahead of time - as the OP said - & you can always make adjustments on the fly to see various sights etc.
If you need to make time or have a tight schedule, then take US-101 or I-5 - & leave PCH for another trip!
6.) If you prefer not to do the run with your full rig - the plan to use a "base camp" as one poster above did - leave the trailer there, & then just enjoy the drive in your TV or TOAD alone.
Can you tell that I worked my way through college in the early 1970's doing those trip maps & plans at Texaco, from those postcards you could get at the gas stations for your summer vacations!!??