I've found a really ugly example and checked this effect more carefully and here are the results:
Vanilla textures:
Vanilla textures with the ENB fixes, the difference is rather subtle:
Vanilla textures, mapping rescaled from 100% to 300% in NifSkope:
Different textures set (1024x1024 normal map, vanilla was 512x512, mapping 100%):
Another textures set (2048x2048 diffuse and normal map):
Vanilla diffuse texture 1024x1024, 2048x2048 normal map:
you can clearly see that the snow effects depends on the quality and resolution of the normal map (it controls where the snow is applied), and, of course, on the mapping themselves.
The same mesh with corrected mapping and 2K textures:
There is a mod on Nexus "Enhanced textures detail (UV-tweaks)" which may be useful in that case (I'm personally using it).