Open plans for 2 weeks in December

Hi everyone, me and my wife have booked flights for the end of this year as a honeymoon/ 30th birthday trip (22nd December 2024 until 5th January 2025) and we are just starting the planning for it and need help!

I'm a bit worried as I know Christmas/new year is a very quiet time to travel and not sure where will be open when we get there.

We have some ideas but nothing booked or set in stone yet other than the flights. We like the idea of private onsens, ryokans, nature along with the busier areas and things to do. We are also planning on doing the Disney parks while we are there (I can hear the boo's already, but this will only be 2 days of the trip)

We like the look of a few places so far, along with the obvious Tokyo, Osaka, Kyoto, we have marked up other areas such as Kanazawa and Nagano.

If anybody has any tips or recommendations or even ways to plan the routes it would be hugely appreciated, feeling a little bit overwhelmed by options. Thanks everyone!

Ps. We will be flying in and out of Tokyo Haneda airport.