Max angle,
Very well written post, I must say.
This has never been considered in the USA (to my knowledge) and as most of my flying has been in the much warmer more temperate climates, you may well be correct.
It would seem to me however that with more moderate cold temperatures, the difference is not worth worrying about.
Having said this...do not intend to fly where the temperature is -20C...too darn
cold! 