We sure did encounter enough low temps above a nightly Siberia, -76 was the lowest I ever saw in dec 1990 (one of my few written down "records").
I remember around -37 or -38 the low fuel temp wrng would pop up in the 744, but then it was already in a down cooling mode and You had to be careful it did not just keep on dropping. As most pilots we did not want to give up our sometimes difficult acquired level (huge time/dist separations used by the Russians), so all was left was to increase speed, I touched m.9 a few times, knowing the beast was certified (or tested I believe)till at least .92.
Later our company used a computer tool that had all the variables in and warned of a possible low fuel temp during prep. You could then decide upon taking extra fuel for speeding up.
Once during an extreme cold spell at high levels near Iceland we ran into problems with the fuel at the lowest possible allowed for that type of fuel. (that still had some 3 degr margin before actual start of freezing.
Already at max speed, we were trapped with planes below and above us, ATC (on HF) giving no help or solution. Later I heard that a lot of other planes were running into problems that night over icy Greenland.
I was close to calling a mayday and doing the NATL decompression manoeuvre to get lower.
OK, the problem will dissipate in future with the global warming, at which I can be blamed too with 18000 hrs on mainly 3 and 4 holers.....plus some three quarters of a million car kms...
