Is this a good idea? Nagano overnight stay

Many months ago I booked a cheap 7 night hotel stay in Tokyo meant to be used as base to explore things both in the city and without, including an overnight stay in Kawaguchiko without having to lug or store luggage (just leaving it in the Hotel and traveling with a backpack).

Now I'm considering adding another similar trip but to Nagano..

Basically I'd get on the Shinkansen early, get to Jigakudani snow monkey park, stay at an hotel in Yamanouchi, then early morning next day leave to Nagano, get on a bus to Togakushi, then come back to Nagano station and return to Tokyo. Alternatively, I could overnight next to Nagano station instead of Yamanouchi.

Btw the dates would be 5th-6th December, Friday to Saturday.

I would really like to visit those two places, though I'm aware there's quite a bit of travel downtime. That bit kinda irks me. Anyone did anything similar have any feedback?

If I don't do this I'd stick to the original plan of visiting Shimokitazawa and Koenji, which, I'm sure are cool, but I'm not mustering much excitement having already explored most other areas of Tokyo. I guess going to Mt Takao could be an alternative? Without an overnight stay though.

Thanks for any advice