Sunshine Coast is another great drive.
Starting off with a 45 minute ferry ride from Horseshoe Bay to Gibsons and Sechelt area. Most of the road is inland from the coast but good road. Lots of twists and turns but easy to navigate with trailer (have not actually towed our trailer up there).
Further up the coast you catch another ferry (this one is free) at Earls Cove to Saltery Bay connecting to Powell River. It traverses Jervis Inlet, a very scenic ride throught the Coast Mountains.
There is a Provincial campground 4 km north of Sechelt on Hwy 101 called Porpoise Bay. Another campground between the Saltery Bay ferry terminal and Powell River called Saltery Bay. Further up Hwy 101 north of Powell River, near the end of the road, is another cammpground called Okeover Arm Provincial Park. That is near the town of Lund.
There are no doubt some private camp grounds available but I have no experience or knowledge of them.
Skoomchuck Narrows is an attraction to visit. It is accessed from the area near Earls Cove. A narrowing in Sechelt Inlet which has some incredible tidal currents popular with the kayaking enthusists. Not so much with the sailing community unless you time it just right!
From Powell River you could do a circle route onto Vancouver Island landing near Comox and Courtney.
Taking a ferry to the Sunshine Coast involves only one fare which is a return fare. There is no other place to go from the Sunshine Coast so you have to come back!! The ferry from Powell River to Comox would therefore already be paid when you boarded at Horseshoe Bay. (Likewise if you returned back the way you came to Horseshoe Bay.) Of course you would then have to pay for ferry to get off Vancouver Island back to the mainland.
This is a great trip to make in September when the holiday traffic has died down and families have returned back to school. Takes the pressure off getting a camp site and catching ferries.