Oh mentioned that it may be better to go through the Alpine route and stay on route such as Murodo. Can you please explain what you mean via this ?In the original post you wrote "Nagano 2 nights- day trip Alpine rote".
If you mean Nagano to somewhere on the Alpine route, you must take
the same route twice (return trip). I think you might better do the one way
trip, from Nagano side to Toyama side. Please see their official page.
https://www.alpen-route.com/en/about/introduction.htmlThe route is rather long and the fare is rather expensive so I recommended
relatively cheap "Option ticket".
http://jrtateyama.com/e/Among the route, Murodo is the highest point and on September/October,
you can hike there (or somewhat lower Midagahara). If you stay there, you
can enjoy the mountain scenery in the evening and morning. There are some
hotels/huts around there and you can choose according to your budget.
Of course you can "day trip", but even in this case you might better go
through to Toyama side, since it will save your time and money. In this
case, you should go through to Tateyama or Toyama or Kanazawa.
Sorry, the following url might not work. If so, please copy the entire url and paste it to the url window of your web browser.
http://www.alpico.co.jp/access/ticket/pdf/panf701[1].pdf