Shared gender outside onsen near Matsumoto

My husband and I are arriving in Matsumoto on 21 November 2014 and have one extra nite in the area before travelling by train on 23 November to Kyoto.

We would like an outside shared gender onsen experience. I am considering either a day visit to Shirahone onsen returning to Matsumoto for the nite of 22 November or bus to Shin Hotaka onsen as a day visit or staying the night then bus Takayama and train to Kyoto.

I am looking for bus timetables for either of these trips and any ideas on the best way to get an outside onsen experience.

Ryokan Awanoyu in Shirahone has a large mixed outdoor bath.
http://www.awanoyu-ryokan.com/awanoyu/english.html

The winter bus schedule for 2013 is here; it'll probably be the same for next winter:
http://www.awanoyu-ryokan.com/img/bus_new.pdf