Many thanks for your thoughts, folks. I was wondering if it was all a bit too much for one day, and it looks like it is.

I'll keep a trip to Matsumoto in my plans, since I really do want to see the castle and ginnyfsf has given me so other ideas for the area.

I'm still giving some consideration to Yamadera. It interests me, but over 1000 steps are giving me some cause for concern. The general "wisdom of the Internet" suggests it only takes an hour to reach the top - I suspect it would take me longer!

Again, many thanks.