Outstanding painting. Personally, I think the snow itself is perfectly fine, but I think the overall impression suffers a bit from the base edges being a bit too warm a brown. As it stands, it reminds me more of frosting on a chocolate cake. It's probably not an option due to having to rework all bases, but using a colder, darker brown, probably with some anthracite or Panzer Grey to dull it down, might result in a colder overall effect.
I wouldn't overdo the tracks. I'd say those are perfectly fine just like they are.