There are not much, but a few snow maps out there.
The one that's most known among us I think is Negrumir's "Winter Lodge". I think Negrumir was pretty much the pioneer in snowy maps.

This thread is for tricks on how to make snow and ice, and all that. Here's a few

1. Snow heaps: Use colonial corners, lower them so that you only can see the top. Clone one, put the clone right next to the original. Now clone both, put them near the first two pieces, but don't line them up. Clone these pieces and mix them up jumbled, until you get a white mass on the floor that looks like snow. 
This trick makes really cool looking snow, but is pretty much useless for large areas, because the framerate just gets awful. However on small areas you could use this as a fill-in, given that there's enough space left on your map.

2. Glaciers: Use fort pieces, jumble them together, so they look like a white rock. Of course, you have to hide the brown part. Looks pretty cool if done right.

3. Ice: Use fort pieces as the floor, hide the brown part. These are the only pieces that look a bit like ice at all.

4. Snow tops: Use tombstones and put them on any object's surface to make it look like there's a heap of snow on top of the object.

5. Small snow slopes: Use tombstones also. Place them on the floor, around objects. It has a nice effect, as it makes objects look as if they stood within a snow heap.

Got any more tips? Post them here...

Wait for fc3 and a colour pallet 

Jumodu had a nice snow map whit wild animals.
I think he deleted the map.

Winterlodge is the best snow map out there.