If you want to stay in a place which has the postcard picture of Santorini, then Maria's villa is the ideal place for you. Everything looks like on the pictures and Oia is the cuttest place we have seen on the whole island.
Maria will be easily accessible by phone, but maybe like us you will never meet her. So be better prepared than us and ask her enough info about how to reach the villa (a map for example), where to park, which restaurants may be open and recommended, etc.