Same water sources as a touring rider needs for drinking - as mentioned, just load up at the very end of the day on your way to stealth camp. Ideally I like hit camp with 4L... 1L evening shower (cold is fine, I use my dirty Sawyer bladder and a spare cap with holes drilled it); 2L for dinner, bfast, dental hygiene, evening cocktail; and 1L to ride out with next morning. As temps drop, heat water on stove, and/or switch to sponge baths. Same routine backpacking. I have a miserable night when caked with the day's dried sweat.