The Great White North is appropriately named. For six months of the year, the Yukon is blanketed in snow, and in the Northwest Territories, north of the Arctic Circle, where this ice road journey will end, winter lasts even longer. The Arctic Ocean itself freezes from November to April. The Dempster Highway was built 31 years ago across the tundra to link the oil-boom town of Inuvik to the rest of Canada. The highway is the artery to the Arctic. If the Dempster closes, as it does each spring and fall when two river crossings are impassable, food has to be flown up to Inuvik, sending the price of a pint of milk to $4.

A brief stop at the preserved Klondike gold-rush town of Dawson City, where former brothels are now hotels -- the casinos are still casinos, even though the burlesque shows have become blush-sparingly tame -- gives us a last taste of civilization for 48 hours. Eagle Plains is the only settlement for 300 miles north. The isolation and lack of human interaction on the empty highway is eerie at first. But time inside your own head is a rare commodity, and driving on a road where oncoming traffic can be counted on one hand in one day is even more rare.

Everywhere since leaving Whitehorse, the smart elicits sniggers. The forecast of blizzards beyond Eagle Plains only adds to the jocularity. "You'll never make it through to Inuvik," warns Jim, a trucker. Trucks, big trucks, are all that count north of the Arctic Circle. "Forget it," he says emphatically.

The reality is that the smart turns out to be perfect for the Dempster. With spares adding weight to the rear driving wheels, it sticks like glue to the ice and snow. With the help of the rarely extinguished traction control, it grips the permafrost when Jeeps and other more fancied Arctic fare are spotted buried up to their door handles in snow.