We use clean bottled water for drinking and cooking and always have enough for any given trip.
Prior to arrival,we try to ask the locals or call the local forest ranger for a water source such as a spring. We fill four 5 gal water jugs and transport them in the bed of our pickup. The rangers have always known where to get water in their district.
When we get to our spot , we fill the trailers 90 gal water tank with spring water or (if we have to) water from a stream using a 12v. marine bilge pump and lengths of clear hose.
Being that we never drink the water from the trailer tank, we are not concerned about it being pure. We do sanitize the trailers water tank on a regular basis.
In the past, I have cut a 6" hole in the water tank to gain access to the inside to really clean it out. A removable marine deck plate is screwed into the 6" hole to seal it. (this can usually only be done if you have access to the top of your freshwater holding tank)
We use a standard store bought one gal water jug with a small 1/8th " hole drilled at the bottom for brushing out teeth and washing hands. Its gravity fed and use a golf tee to plug the hole.
In the past I have used solar panels but have found the portable genny the better bang for the buck using it in shade, rain or shine 3 hrs per day. I recharge my bank of 12v AGM grp 31 batteries.
LED lights, 12v as well as portable battery models do the trick along with TIKI torches outside.
The only 12 v draw in my trailer is the circuit board on the fridge while running on gas. Everything else on board gets an on/off toggle switch to kill power during off times on standby mode. I only turn on radios/tv/detectors to monitor or use the device as needed.
My water pump and occasional furnace fan is my biggest 12v draw but that's limited use.
I monitor my battery banks voltage with a volt meter and never allow my batteries to drop below 50% before recharging.
Happy boondocking,
Bob