Why diesel car works better in snow than petrol car?

The only reasons I can think of regarding this is:

A diesel car would/could possibly be better in snow is the fact that they are mostly a bit heavier than similar petrol cars.

Heavier car mean better grip on the road/snow.

Another aspect is the slower acceleration. This is preferable on a semi-slippery road.

There are on the other hand other issues with diesel that makes it a worse choice with increasing cold.

Diesel can actually go stiff when being exposed to low temperatures.

This is a problem already at -20 degrees Celsius.

The diesel providers (Shell/Statoil/Q8/BP and a lot of others) add stuff to the diesel so that it does not freeze but this is not done all year round.

It is also a common problem to actually start up a freezing cold diezel car.