Rainy day things to do around Hakuba/Omachi

I was planning on going the Tateyama Alpine route and Hakuba Happo-One late next week when I am in the area. However, current forecast is that it may be cloudy and rainy on those days. I understand things may or may not change, especially with mountain weather. I'm wondering if there are rainy day alternatives in the area that might be recommended.
I suppose Matsumoto would be the logical choice. Not sure if there are other things I'm missing.

This art event is still ongoing:
https://shinano-omachi.jp/en/concept/

I only went to the places outside of Omachi (in the countryside) which was very nice. The art was so-so but the setting is nice.
http://bicycletraveljapan.blogspot.com/search/label/NAAF?m=1

Another option is to relax in an onsen all day. There are many in the area.

Buying a rain coat obviously is also a possibility, unless you plan on some serious hiking.

I don't know if you're interested.
I've been to the Daio Wasabi Farm and Rokusan Museum in Hotaka.
https://www.daiowasabi.co.jp/
https://azumino-artline.net/
The Northern Alps International Art Festival is also being held.
https://shinano-omachi.jp/en/
I think it's a good idea to visit Matsumoto Castle, the Matsumoto City Museum of Art, and the Japanese Ukiyoe Museum.
https://www.matsumoto-castle.jp/
https://matsumoto-artmuse.jp/
https://www.japan-ukiyoe-museum.com/
By the way, I think you can go on the regular course of the Kurobetateyama Alpine Route if it's not a typhoon.
You'd better not climb the mountain from Murodo on rainy days.
I don't know because I've never been to Happo-One mountain ridge.

Unless it is a safety issue or torrential downpour I recommend braving it and getting out in the rain with a raincoat umbrella and if you have them some waterproof shoes.

I had two fairly rainy days on my trip I just returned from and they were some of the more memorable days despite the moderate misery of being slightly wet. One day was in Inujima/ Takamatsu followed by a day on Naoshima/ Osaka. The rain in Inuiima made it atmospheric and I really enjoyed visiting Inujima Seirinsho in the rain. The rain had let up by the time I arrived at Takamatsu Ritsurin and it was nice seeing the garden following the rain.

Thank you. The wasabi farm was on our shortlist. I haven't actually gone into the Matsumoto city museum before.
The forecast currently says cloudy so I may take the chance getting into Happo-one and Tateyama Kurobe. Doesn't seem like there is much of a chance for sun at this point. Will have to wait until 2-3 days before still. I know the alpine route has some live webcams, but it seems hard to tell the forecasted conditions. I'm looking at the cities/villages mainly such as from Hakuba, Matsumoto, Takayama.
https://tenki.jp/forecast/3/23/4810/20485/10days.html