Traveling to and from far-far-away Sapporo

Hi, can you please help my family of 3 to plan the most efficient way to travel to and from Sapporo with a JR pass traveling in June 2023?
1) from Kawaguchiko to Sapporo
2) from Sapporo to Kanazawa
3) if it is possible, I would like to stop over in Hakodate on the way to Kanazawa.

Uh! Sapporo is so far away! Do you think it is better to travel on a sleeper train since the journey is so long? If yes, is it covered by a JR Pass? I need to know this because I have to plan hotel reservations too.
Many thanks for helping.

Check out flights instead and maybe just don�ft get a JR pass or one only for the region where you want to use trains.

Is the JR pass valid on the Sapporo - Tokyo line (probably).

Look into flight costs as this can be much cheaper and way faster.

From Kawaguchiko to Tokyo, maybe about a few hours of train journey?
From Tokyo to Hakodate, the train journey is about 4h
From Hakodate to Sapporo, the train journey is about 4h.

There are no sleeper trains to Hokkaido.

Each of you select routes is 9-10 hours travel and transfers. Hakodate will break up the travel a little.

Better off flying or redoing your itinerary as Kawaguchiko to Sapporo to Kanazawa is a lot of traveling since The no Hokkaido locations are so close.

Hokkaido is best to go first or last.
What is the reason why you have to go at that timing?
Other than JR and airplane, there is also a way to go to Hokkaido from Niigata by ferry.
https://www.snf.jp/english/

Essentially just a matter of getting to Tokyo from whatever location you start at and then the Hayabusa to Shin-Hakodate Hokuto, then a Ltd. Express to Sapporo. It's the better part of a day of traveling but I've done it a few times, nothing too crazy in a comfortable Shinkansen/Tokkyuu seat.

Otherwise if time is of the essence then air is the answer.

>Do you think it is better to travel on a sleeper train since the journey is so long?

Haha, you're a few years too late for that unfortunately. I do miss taking the Hamanasu from Aomori overnight with the JR Pass though, RIP the Blue Trains. (;_; )

Consider rearranging the order of the tree location.
Do look at flying, it is faster. You will waste a lot of time getting to/from Sapporo (whole days).

You could start your trip by landing in Hokkaido. CTS (New Chitose) is also an international airport and has flights from Seoul, Busan, Taipei, Bangkok, China, and seasonal from other countries. You could just fly into Sapporo and start there.

You can add a flight segment for Y11,000 with a JAL Japan Explorer added on to an international flight if purchased with your international flight into Japan. ANA also has some special fares.
https://www.jal.co.jp/world/en/world/japan_explorer_pass/lp/
Origin Airport -TYO-CTS. The TYO-CTS flight would be Y11,000 from Tokyo.

You would then only have to work your way southward by rail and wouldn't lose the time on a round trip.