Indeed -20F to -40F is very cold. I think this would be the more impressive headline. Over here we do not go much below 0F, maybe -10F, so -40F is difficult to imagine.

About the south: I used to stay for a while in Austin, TX. During winter we had temperatures below freezing (just ice, no snow). The locals told us that this happens at least every other year. For this some were suprisingly unprepared though, in particular with regard to driving skills, water pipes and building insulation.