Advice for travel between cities please!

Hi all! Will be travelling to Japan for the second time this year in December, except this time with my husband, 14 month old and 4 other adults. I’m in the middle of planning it all now and am trying to figure out the best way possible to travel between cities. Our itinerary is as follows so far:
Day 1: Land Haneda Airport, fly into Sapporo (which airport should we choose?)
Day 1-4: Sapporo
Day 5-9: Kyoto (would it be best to fly from Sapporo into Osaka (KIX) and take train into Kyoto?)
Day 10-17: Tokyo (would like to catch Shinkansen from Kyoto to Tokyo so other family can experience it)
Would above modes of transport be achievable? Last trip we caught Shinkansen between Tokyo-Kyoto-Osaka-Tokyo and found it easy to navigate. I understand it’s a bit silly to start off in Sapporo but family plans cannot be moved. Any help is gratefully received 😊

by Cultural_Section_287