Onsen between Kanazawa and Tokyo

Hello,

I am planning the last leg of my first trip to Japan. I am going to be in Kanazawa for a couple of days and then onto Tokyo for 5 or so days before flying home. I am looking a good ryokan onsen combination en route back to Tokyo. It seems like many are out of the way and difficult to access. Takayama looks interesting, but according to HYPERDIA, it is quite a treat from Tokyo.

Any advice or input is greatly appreciated, thank you in advance.

Not too far off the shinkansen are Unazuki Onsen, Nozawa Onsen and Shibu Onsen. A little further off is Kusatsu Onsen, but I consider it among the best in Japan:
https://www.japan-guide.com/e/e7400.html

If you were to take the bus through the mountains rather than the shinkansen, your route could lead via Okuhida, which is another of my favorite onsen in Japan, but that route is much more time-consuming and complicated to travel:
https://www.japan-guide.com/e/e5940.html