There is an interesting potential court case, if I have ever heard one.

I would think that if the cyclist were riding following the trafic laws with the correct equipment (studded tires?), they would have a hard time proving negligence. But with that said, I am NOT a lawyer or an insurance company.

You could argue that driving a car in those conditions is negligent. They'll still pay if you die in a car wreck.

Good question though!