Winter campaigns

[Maths]

Hi all !
Recently I've played a game on Soviet Storm mod by Akkula (btw a very good mod) but I'm this game like in many other I thought that the winter isn't as harmful as it should be. The main example is rivers. In non-snowy weather rivers are very easy to defend and then are often the backbone of a defense line which is traced along river course. But in winter, the rivers freeze and then are no longer efficient in defense. In a word, it isa better idea to launch your offensive during winter than to launch it during summer : senseless as generals were often reluctant to do so. In my Soviet Storm game it results in a even easier break through of my lines during winter 41-42 for the German forces. In comparison the minus 1 strength point applied to the Germans is very pointless against those 300xp panzer divisions.
So I'm asking if there are any suggestions of what could be done or what should not be done about winter campaigns.
Cheers