I work from a garden studio which has electricity but no running water and have used big buckets for years. One thing you may find useful .... full buckets (of water, glaze, slip etc) are very heavy. I get round this by standing them all on casters - the wheeled garden pot bases you can get from garden centres are ideal, or you can make your own (I've both) so the buckets/bins can be moved around easily. This makes cleaning the studio so much easier as well.
The very best of luck with your studio