Ha ha! I opened this post thinking it was about personal protection against some miscreants!
We have two 7 gallon portable containers. Minimum usage for us is 1 gallon per person per day, probably 1.5. So, about 5 days, at which point we would be ready for new scenery anyway. If we bathe with potable water, that cuts into it severely.
REI sells a collapsible water container that uses very little space. Tuck it away and fill only when you need to extend your time in the boonies.
Almost every small town has a city park. Great place to fill water, use the restroom, stretch your legs, have a lunch. We find that some of the best food comes out of small town cafes.
2019 HR T-250 Quigley Transit, 3.5 Ecoboost, 3.31 LS, Magnetic Metallic