I found short notice just as unreliable as advance, and didn't really fit with my not sitting around waiting but can be flexible lifestyle - nor low population density location.
Even when away from base, in busy cities I work on advance bookings sometimes up to several months ahead. Once again however I'm usually there for other commitments, photoshoots, courses or conferences so need to know in advance.
What I do do is have a definite confirmation time, and these days apply the same deposit system I do for anywhere and any booking bar reliable regulars I've seen a lot of or recently.