When I lived in Ontario in the late 80's, the winters north of International Falls were very cold. Commonly - 20 to - 30 daytime highs Fahrenheit. We used to drive a Skidder pulling 4 logging sleds across the lake ice roads, and the runners would stick above about - 5. When knives were used, we were taught to keep them in our coveralls to keep the steel temp above freezing.
Metal wedges were no problem, and laid in the sled and were pounded on, but were probably not very hard. Of course the knives were cheap, carbon blades... But never tried to drive one through frozen wood.