Here in Finland we have three (or four) different diesel-oils for sale in here: summer grade, winter grade, special winter grade and if weather gets really gold also Arctic grade Diesel. Summer grade goes well to -5c -10c, some even down to -15c.
IIRC it's the paraffine which crystallizes in the fuel filter and prevents flow thru it when using summer grade in winters.
Friend used to drive a semi (well not a semi but a 25m "train") and his longest trips were to Kazakhstan.
French semi joined to their convoy with tanks full of some crappy mid-european diesel which, of course, choked the filter.
I bet that French driver was happy when my friend told him that he's having few hundred liters arctic diesel "Just in case"....