We have friends who live in Wales in the same situation, and one of the things which I know she is very strict on, is the absolute non-use of any kind of pesticide, weed killer etc being used on the garden in case it makes its way into the water supply. They were in the situation of having no running water for several months when the water froze during a very cold spell several years ago, and had to resort to buying lots of bottled water, and recycling almost every drop, to the extent of flushing the toilet only when absolutely necessary. They have several small ponds in the grounds and broke pieces of ice to melt in buckets to use to flush the toilet. They went to the local town to use the launderette, and the water there was frozen as well, so clothes were worn for longer than usual!
They went to stay with friends out of the area mainly so that they could have a shower instead of a wash!