No emission testing to get plates here. I've never even heard of anyone getting pulled over or in any other kind of trouble for modified emissions equipment.
Does she drive a diesel? If so, you guys are far enough North to know about the usual information reguarding the cold weather tools like the block heater, grid heater, and anti-gel fuel supplements.
I used to run Power Service supplement in the winter until I found out that Kum and Go pretreats their fuel with it already. If they're doing it right it should be good down to -40F if I remember right. Much better than the -10F that many other fuel stations offer.