Another long pompous dissertation from James Bond who flies solid IFR while under small arms fire... he should set up his own pilot forum, where only holders of eight gold stripes can join up.
Pprune is mostly a UK/European forum. The UK is rarely -6C or -12C.
If it is, which is extremely rare, prob99 you cannot get to the airport.
The lowest temp I have ever seen since coming here in 1969 was -8C, and indeed EGKK is -8C right now
EGKK 260520Z 00000KT 7000 NSC M08/M09 Q1029 582900//
Somebody I know up north is apparently seeing -19C but there is no chance of anybody driving around up there anyway. The car door doesn't even open, I hear.
If I tried to open the door on the plane in these temps, there is a good chance the door seal will be stuck to the other half and will rip off.
If one was parking outdoors and had an engine heater out there, unattended, the engine heater would get stolen pretty quick (at all but the H24-secure airports, and most of the latter do not allow GA parking anyway).
Elsewhere in N Europe, things get colder and -20C is common, but they tend to have equipment to deal with it..... like hangars
I seem to remember that there was a problem with some of the multigrade/synthetic oils if you changed to them after running the engine on non multigrade for some time. IIRC it was caused by lead build up with the std oil. The lead was then removed by the multigrade which gave problems with oilways blocking as so much of it was dumped into the oil.
I made that change twice (1x when new and 1x after the Lyco crank swap job) and never saw this.
No idea where this story originates but it could be with the pre-1960s crankshafts which had what I vaguely recall were calles slush tubes and those had a history of getting bunged up anyway; somebody tried to sell me one of those in 2005... But I never saw any big lead % in the oil analysis anyway.