The fuel suppliers regularly change the fuel that they sell during the year, to match weather conditions. The best bet is to buy your fuel in the same location where it will be cold out, and that fuel should be fine. You are more likely to have problems if you fill up in a warm area (where the suppliers don't move to winter fuel) and then drive to a cold area, and leave the vehicle at ambient for a period of time.

If you are really concerned, you can buy fuel treatment that lowers the gel point, but you shouldn't have to.

Not sure on your ambient temperature (on one of my trips to Australia, near Meekathara, it reached 45C, not too cold out), but here in BC our summer diesel fuel gels at about -12C, so if we are getting to winter conditions the suppliers adjust their supply.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue