Looking for a small room

I am looking for a small room. I spend my time walking and bussing the country, and will be away quite often. I need to have access to a bathroom, and an electrical plug in my room for a kettle.
I am quiet. I do not smoke, drink alcohol or take drugs. I do not use kitchens to cook, only to wash dishes up. I am the ultimate tenant, you don't even know I'm here. My recent landlord can verify this. I can live anywhere in England and I am looking for something as cheap as possible over the next year. My budget is £300 max. no contract is neccessary, this can be done on a month by month, with one months notice, but I am also happy to stay for a year