Cycle-touring, Expeditions, Adventures, Major cycle routes NOT LeJoG (see other special board)
I didn’t have much success either. I suspect I wasn’t using it right- in terms of the length of time ahead in making the booking, most of them (understandably) want more than short noficr but agree with the other respondent that maybe you are planning too far ahead. Having said that we found plenty of places to stay either B&B or hotels or camping. Didn’t try warm showers but there are plenty of listings.