well since i'm too late to this discussion i guess, i thought of something like cp_everest. being there is a giant mountain in the background and it is snowy, not exactly trains on the side of everest but what the hell right? But looks like youme already decided
"Snowpack" has got to be the worst of the bunch Icemoon would be better because it just sounds cool. D:
I find Latin words work well for map names I'm currently doing a snowy CTF map called ctf_nival (nival is Latin for 'a snowy environment')