Thanks for the kind words, guys! 
Since i personally find the way someone achieved an image always interesting i thought I’d share a bit of the process with you: 
(I forgot to turn on the snow-layer in these images
)
Here are the stages:
In blender:
“raw” rendering with Cycles (~300 samples. in the final image i used 2048):
after the compositing nodes:
After that, I saved this image as a 16bit tiff-file to be able to grade it properly without creating nasty artifacts.
I had to use Photoshop here because Gimp does not support more than 8bit at the moment.
If you open the last image you can clearly see some color-banding going on in the sky. The solution for this is to add
a little noise to the image.
I hope somebody found that helpful or at least interesting 