Fodor's Travel Talk Forums - Booking a room in Magome/Tsumago the day before?

My wife and I are making our third trip to Japan in late September. As of now we plan on leaving Tokyo early on monday 9/24 to go to Magome and then hiking to and staying in Tsumago. Our concern is that if it is raining hard that day it would be a lot of traveling for not much enjoyment. So our thought is that we would not book a hotel in advance for that day and if the weather cooperated we would hopefully stick with the plan and find a room with short notice to stay in Tsumago.

Does anyone have any experience with booking a room in Tsumago(or someplace close to it) either the day of or the day before? I read one ryokan review where someone mentioned they were in Magome and the tourism office there helped book them a room for that night in Tsumago, so perhaps that is an option. Thanks!