When we RVed to Yukon and Alaska, we'd plan one night every 7-10 days in an RV park to clean up - laundry, shower, wash vehicle, etc. In between, baby wipes were used for human clean-up, or a dip in a lake or stream, which are very clean here.
For water fills in between, I'd ask at the places we were stopping for fuel. If they had an RV park too, they'd usually tell us to just pull around there and fill up, or they'd point us to the spigot on the building. If you're filling with fuel, many places let you dump septic tanks at no cost too.
Some communities have free water and dump stations at a community facility. Watson Lake YT has a lovely spot at Wye Lake park - we also enjoy our lunch or a dog walk there.
Always check the water before filling - some places have a high mineral content and the water smells and tastes odd.