Hotel near shopping/dining in Chubu region

We are visiting Japan last 2 weeks of the year, and contemplating spending 4-5 days in Chubu in additional to Tokyo. We are pretty familiar with Tokyo but have never been to Chubu.

We want to take day trips to Monkey Park and various temples. Where should we stay/base at that's most convenient? Ideally we want to stay in an area that's have good access to trains/easy for luggage since have kids/with tons of options for shopping/dining (think Namba for Osaka or Ikebukuro for Tokyo). Are there such locations in Chubu? For example, Nagano or Matsumoto?

And anyone have suggested itineary for Chubu? Thanks in advance!

Matsumoto is nice for a night or so, I've never stayed at Nagano, but what I think would tick a few boxes is Karuizawa. Very nice, trendy town with heaps of restaurants, fun shopping (and a big mall thing if that is what you like), and handy to the shinkansen line with a highway bus hub as well (good launch pad for Kusatsu Onsen). Le Grand Kyu is an excellent and reasonably priced hotel there.

Chubu is a vast region, not a metropolitan area like Osaka or Tokyo. So I think you first need to make a list what you want to visit and then select a town , or more likely MULTIPLE towns where to stay.
Karuizawa is nice, but Karuizawa-Matsumoto is 1,5-2,5 h in train one way. Karuizawa-snow monkeys is somewhere around 3 h one way.

Also actually the attraction of Chubu is that it is NOT so packed with cities. So you might want to reconsider and stay in more rural places( eg some onsen resort) to enjoy nature and a lack of entertainment.

Enjoy your trip to Japan!

I really like Nagano, I think it's underrated. I liked where I ate there but it's not somewhere I go to shop. It's no Namba or Ikebukuro. But it's a lovely small city. It's the closest city to the snow monkeys

Kanazawa is part of Chubu. It's hours from the snow monkeys but definitely has shopping, lots of restaurants and an amazing garden as well as some great museums.

But where is the best place to stay depends on what you want to do and your budget. I thought Karuizawa was sort of expensive for what it was so decided to stay elsewhere.

Good luck