That narrows things down some ( elec. and water ).
Take a look at Moonshadow in Merritt. Moon Shadows RV Park and Campground - Merritt BC, Canada
We enjoyed a stay there two or three years ago. Water, septic and electric sites near the Coldwater River. Not jammed with motorhomes when we were there.
A few minutes drive to downtown for groceries, a latte and beer.
It appeared to have become run down after owner had a heart attack, but last I heard it was back in shape.
There are drive through sites, and, if you want to try boon docking, you could just move further back, away from the "crowds" ( and closer to the river ).
Couple hours on the road and you can be at the Grist Mill in Keremeos. Best check availability. There is a foodie event taking place there sometime soon and they only have limited sites.
Clayburn RV Park is also in Merritt, if you like the sounds of a lumber mill running 24/7. It has a free sani-dump and there is another free dump at Canadian Tire.