With roads north of the arctic circle. It looks like it would be difficult to do that without crossing into either Sweden or Finland too, which would be an issue for Snowden.
But Norway is a Nato country so it's a trap. Don't go there.
With current pressure from Russia even neutral counties like Finland would probably gladly extradite Snowden to US.
[1] https://www.google.co.uk/maps/dir/Moscow,+Russia/Oslo,+Norwa...
[2] https://www.google.co.uk/search?q=weather+olderfjord [3] https://www.google.co.uk/search?q=murmansk+weather+10+day+fo...
Sure, but nothing that can't also happen in a car on a small backcountry road at night. And anyway if he takes a passenger ferry he'll be constantly surrounded by hundreds of other people which is a hell of a lot more collateral damage to take into consideration if you're genuinely concerned about someone causing an 'accident'.