Tokyo alpine route iteniary

Hi I'm planning a family trip to Japan.
We have had a six week backpacking trip in Japan before we had kids and loved it! We travelled from Tokyo all the way to Nagasaki last time, visited lots of bucket list paces. This time it will be very different with a 4 y.o. and a 1.5 y.o. i would like your thoughts on ideas and feasible on the rough iteniary. We are travelling in October and have 16 days total, and haven't booked anything yet!
4-5 days in Tokyo, staying ryugoku area, visiting odaiba area, Disneyland and local ryugoku area
1 day (2 night) in Matsumoto, (2nd visit, but I think the 4 y.o will love the castle)
Alpine route and staying over night at Tateyama.
Day trip to kurobe gorge, and finish at Nagano
2-3 nights at Nagano, local temple, kids ninja park
1 night at yamanouchi, visit the monkey park.
Last 4 days in Tokyo, Ueno zoo, science museum, harajuku etc maybe the other Disney park
Do you think it's doable? I'm thinking bring a umbrella stroller / a carrier. From what I have read, there aren't too much hiking involved, is that right?
Also do you think we will benefit east JR pass?
Thanks!