Hokkaido and Northern regions

Hi everyone,
My partner and I are planning to visit Japan in autumn 2024 and this time we'd like to visit the northern regions, including Hokkaido.
The plan is still at its beginning phase and any suggestions are more than welcome.

The trip would start from Tokyo around October 18 until around November 4.
We would love to see Koyo, the japanese colourful foliage. So that being said, do we still get to see it during its best time (even in Hokkaido?) or the trees would have started losing their leaves and colour?

I've already been to Sendai and Matsushima in the past, in case any suggestions are coming up for our itinerary=) Plus we would be travelling around Japan by train and public transport.

Thank you

Add a flight from wherever you enter Japan to Sapporo to save some time. To get around Hokkaido, the best you get are express trains as there are no shinkansen except from Hakodate south, but they make pretty good time. I would look into renting a car from one of the stations to drive around the national park areas such as to get to Lake Mashu north of Kushiro. It also makes it easier to go to some of the more remote places that aren't covered by trains and the buses are few.

Fall colors vary every year according to rainfall and temperature, but the page shows averages and guesses for 2024:
https://www.youcouldtravel.com/travel-blog/autumn-leaves-festival-koyo...

Heading south, the Oirase River hike has good colors and the boat ride across Lake Towada is scenic.

You could also take rail lines south along the coast from Hachinohe. The Sanriku Line offers a special slow train with dinner.
https://www.ana.co.jp/en/jp/japan-travel-planner/iwate/0000025.html