@chruzzie

I wouldn't if both fans are crook

There are two fans BTW so if one is working it may just do the job. If you turn the A/C on and a fan activates you may just get away with driving 100klm so long as you keep a close eye on the temperature.

 

Basically, it will likely be OK as long as the car keeps moving. But if you do sustained high speed, like on the motorway, then hit traffic and come to a stop, the car will probably overheat. Ask me how I know.

Follow Kevin's advice, or get the local mechanic to rig up a switch and some wire that powers at least one fan directly that you can turn on from inside the car should you need it.

In the absence of the above, I'd do the trip late at night when the air is cold and the roads are clear, keep to a gentle cruise in top gear at under 2500 rpm so that it stays off boost and cover the last few miles with the revs as low as possible so the engine is as cool as possible when you stop. And in the last several miles, crank the heater to full and the blowers to max with the windows down to dump as much heat as you can before stopping.

But it's a risk. A tow is much cheaper than a new engine.

 

Thanks PacoJones, I'm going to try a late night trip with your suggestions

 

Given the cold temperatures in Hokkaido, would the natural airflow from driving be enough to keep the engine from overheating?

If it's cold (relative I know) and you are driving at highway speed, it doubtful that your fans would ever be running.
Driving at highway speed will put more air through the radiator than the fans will.
Speeds above 30 mph /48 kph will typically turn the radiator fans off.
Stops and slow driving, especially in warm temperatures are when the fans normally kick in.

As noted, you could hook up a jumper to the fan(s) to keep them running if you are concerned that you'll hit some heavy traffic. I'd add a jumper with a quick connector under the hood that can be plugged in in the event the engine warms up too much. It can be easily removed once you have the car repaired.