WA state and Vancouver / Whistler

We’re looking into a trip next summer to WA state and possibly Vancouver & Whistler. In WA we are considering Mt Rainier, Olympic National Park, San Juan islands, and maybe North Cascades. In Canada, we were looking to spend a few days to see Vancouver and perhaps go up to Whistler.

Any advice / suggestions for getting around these areas with a trailer, where to camp, places with hook ups, perhaps WA state campgrounds in the area, must see areas? Olympic is pretty spread out and it seems some of the roads might be tight with a trailer. We’d prefer to minimize the number of sites we camp in and just take day trips if practical. Same questions wrt Vancouver – is there a place to land the TM with reasonable access to the area highlights?

Cheers