The -40c 850s shown in Northern Siberia on the 18z GFS and their potential journey towards is fascinating, exciting but also a scary prospect.
Let's face it, even if that airmass propelled itself toward us it would inevitably be moderated but if it was sort of -20c 850s for any period of time around 5 days or longer, this country would be in serious trouble.
I remember looking forward to the 2018 BFTE and when it came my boiler kept cutting out due to condensate pipe freezing and eventually the heating broke completely as a valve went in the CH system. Once this happened I was praying that the weather would warm up and go above freezing as my house was being kept above 10c by patio heaters etc and it was unbearably cold with the easterley near gale howling through our dog flap, that ironically faces east!
If a more severe, prolonged version occurred this year, especially in the main height of winter it would be incredible/ epic but would feel for people in peril. In these situations the cold can gain the upper hand and deliver such an impact on our normal routines and life, i.e. no thaw, heavy snows, burst pipes, unbearable windchill. The likes of which we never normally see.
Having said that it would assist lockdown, reduce traffic and keep people inside.