Quite a few years ago I had a 94 golf turbo diesel.
I spent some winter time in Winnipeg. It’s always cold and windy there.
I’d never had to plug the car in before. I’d also never had fuel felling before.
I was likely running 15w40 for oil hence my issues.
Then I lost my overnight plug in. And the day time one at work...
So I got a piece of stove pipe with an elbow, the burner from my deep fryer, a 20# tank of propane and would pre heat with this thing roaring away under the car on the side of the street. Winnipeg being the car theft capitol of Canada at the time..... no one bothered my old beast. Even the walkers and joggers avoided it! 20 min of preheat was enough for it to light off.
Fuel additive was also necessary to prevent the jelling. Maybe the fuel stations hadn’t got winterized fuel yet. -30, -40 is not easy on anything.