Hi,
Sorry for the late response, i have not had so much time to work on it lately 
The landscape will be really big and since i want to have that sink effect on maybe 70%, it will probably be a lot of work to make meshes for it. Do you know if it is possible to make that effect by editing the material? So for example if i have a material with a LayerBlend with different textures, the weight of that layer in a specific area of the landscape would devide how much it should sink down into the snow.
I also took a look at the grass material and at a first glance it looks a bit complex so i think i will have to learn a bit more about the basics of the materials before i digg in to that 
Thank you for the help.