In the late 80's I took two friends in off the Gunflint for three nights early in November. On the third night temperature dropped well below zero. There was open water on the lake we were camped on but both exit options were frozen tight. We ended up portaging  (my fine 85# plus canoe) five miles to the Gunflint and then walking another couple of miles back to the car. A mile of  bush whacking led to an old cart way that led to the road.