Pretty simple idea. The "snow" would be a lot of white spherical objects packed together. The snow should easily deform upon impact(pretty weak). It doesn't need to be affected by environmental temperature. It would spawn in high enough quantities to actually cover a road in the snow. The weight would be incredibly low per piece of snow. Something like this, but with the snow mentioned above. Essentially just edited values and resized rocks.
Sounds great in theory but it would never work and even if it did it'd look terrible and not like snow.
Making small, very light spheres that are stable is something very complicated. But in addition to making it less greedy for the game seems almost impossible to me, so I wish you good luck! (I myself made small very light spheres (0.4 kg minimum), if you want to see the result, it's here: https://www.beamng.com/resources/pétanque-balls.25265/ )
That's the thing, to make it not look terrible, the current system would need to be improved. This would snowball into the deformable terrain idea for the vanilla game. This is something possible without having to devote months to making it look and behave snow-like. Thanks for the mod suggestion, it does look similar. Though, it passes under the snow plow
