This is incredibly interesting I am surprised that there is not more interest in here!
It looks to me, that we have a lobe of the PV, very similar in strength to 18th,19th and 20th December 2010, but further North and West this time, rather than right over us, but still close enough to have a significant influence on us.
Anyway the origin of the low/PV lobe and the area the air will travel over as it reaches us, is very cold. I agree with quantum, could be some very low minima up north over any snow fields that form. Looking forward to your photos/reports Joe, Saint et al if the charts play out as currently shown......
Near Leatherhead 100masl (currently living in China since September 2019)
Loving the weather whatever it brings, snow, rain, wind, sun, heat, all great!