I have a friend, Wallee, a fellow concert programmer in fact (he used to work at the wonderful St Ethelburga's Centre for Reconciliation and Peace), who is looking for a cheap room to stay in from mid April till the third week in June when he is going to Greece to work for the summer. He has been house-sitting for friends in Frome and now in South East London. I said I'd ask around. His budget is not huge. So please do let me know if you know of anything.