You can use ski troops to speed up contact but remember that they don't get their movement bonus on roads (maybe snowplow cleared them).
Its been a while since I last used them but if I recall correctly the ski troops have the same speed over flat snow as normal infantry have over flat clear.
I feel for you, Ketch. It's 3/1940 on my 200 gamer, and I'm just about fed up with the snow, cold, and fight-till-we're-all-dead Finns. I've been doing it the hard way, I admit, with only some ski scouts or snipers as support.
One question, your off board 122's, is that 4x guns (one battery), or 4x batteries???