Here a model which I build many years ago, just when I started collecting tanks in the scale 1/144.
From a modeling magazine I got a good idea about a bleaching material what I could use for snow.
As a basis I took a 12 mm cork coaster which you find in each Swedish furniture store. On the top I modeled the landscape in a combination of gypsum and paper. Later I painted everything in dark brown and scattered it with this bleacher powder.
The only thing I forgot where the tank tracks in the snow. Therefore I tried a modification which I later removed.