We did our first loop in this area in June 12 years ago. It was rainy and windy when we camped at the Nakusp hot springs - enough so that I had problems keeping the dining fly up. But soaking in the hot pool at dusk with a light drizzle and clouds shrouding the mountains made up for that.
On a later trip, we did a dusk soak at Miette Hot Springs in Jasper, and had a curvy 17km drive in the dark back to the Pocahontas campground by the highway.
The only free hot springs that I've used in BC is Lussier Hotsprings on the way into White Swan Prov. Park. That's right of a gravel logging road. The only clothing-optional springs that we've used were in remote parts of Idaho and Oregon.