We a,ways run with our fresh wate tank at around 75%. We have been several places where the water was not available due to freezing/outages and this is in southern Texas where you do not expect that type iofof freeIng, one time, we encountered this 4 days in a row. We had onboard water so life went on as normal for us. When we are just stopping overnight at a campground, we never hook up water and sewer. We have onboard water and just hook up the electric. It makes it much easier to set up/take down.