Renting a car in winter Hokkaido is getting more popular for foreign traveler. Why don't you try to drive a car on winter road? Your travel must be fun more and more if you travel with a car. Hokkaido does not have much public transport, especially countryside.
Some foreigners have reported driving a car in winter Hokkaido. Please refer these.
•Life's Tiny Miracles, Self-Drive Hokkaido: https://goo.gl/SA5gyF
•Hokkaido Goverment, Winter driving Hokkaido: https://goo.gl/VJMu9p
•Driving in Hokkaido in winter, Ok or silly?: https://goo.gl/Ab3C5p