Good breaks along Furano - Hakodate - Otaru

We'll be driving from Furano to Hakodate (2 nights), and then Hokodate to Otaru in early August. As it's a long drive, would really appreciate any suggestions for any good places or rest stop along the way for a quick stop.

Thanks,
Heiz

What an unusual route! Are you sure you can't do it more efficiently?

Nice stops between Furano and Hakodate are Noboribetsu and Lake Toya.
https://www.japan-guide.com/e/e6750.html
https://www.japan-guide.com/e/e6725.html

Nice stops between Hakodate and Otaru are Niseko and Yoichi:
https://www.japan-guide.com/e/e6720.html
https://www.japan-guide.com/e/e6707.html

On both journeys, you also pass Onuma Park:
https://www.japan-guide.com/e/e5356.html

It sounded crazy too when we start searching info on the route, LoL. Great info there Uji, will likely add Noboribetsu and Onuma Park into the plan!