I understand that it's good to inquire several days ahead with potential guest. But I'd guess that lots of tourers don't have a hard fixed schedule, don't know how many miles they might ride in a day, and don't have fixed overnight points.
Am I wrong? If not how are you and others dealing with this issue?
Are tentative/potential inquiries acceptable; i.e. "Hi I'm riding from A to B in the last week of May and you are along the route. I'm not sure how far I get and where my overnights will be. But if I'm near your place would it be OK to call you and inquire if I can stay at your place that day."?