I did it.
I packed up my life and moved to Nagano, I bought a house literally at the foot of a ski resort for the price of a new medium size car back in Australia.
But its not easy, without knowing japanese its downright painful if you dont have someone to help you through all the paperwork. Having said that the rewards are enormous if you pull it off and the countryside is beautiful even without snow, at least in my area anyway.
Imo there are 2 Japans, city and country. The city (tokyo) is full of salarymen who wont make eye contact with anyone, it would be a very lonely place to be on your own.
The country is amazing, filled with wonderful people who smile and nod at you in the street, a vastly different environment to the city, the catch is there arent as many "real" jobs although there are still plenty of english schools around, you could possibly get a job at one of those.
You also have the ability to make money in the winter letting friends crash at your place cheap, cheap transport to the skijo and grow lots of food in the summer time.
In short you will have less money but you will also need less money.
Choose your lifestyle.
If you are set on Hokkaido, rent a car next season and travel around, take note of areas that suit your needs, check local real estate places and get their website addresses so you can constantly check them. When you find the right place jump on it.
PS you need a visa to work and live in Japan but not to buy a house.
And learn Japanese, start today. Spouse visas are great but its not likely you will get one with no Japanese skills