You would think that. However, its actually notable how much hard packed ground of winter figures into the Russian big wins throughout history. Stalingrad was caused by a Operation Uranus in late 1942. The Red Army saved Moscow in winter 1941 because they shipped their Eastern Siberia army to Moscow via the railway. The Red Army was much more foot-borne in those days but having hard cold ground mattered as they were trying to move large forces at key vulnerable spots in the German lines.
The traditional campaign seasons in the steppe are Winter when the ground is frozen and the hottest, driest part of the Summer. The muddy season which starts sooner than Vladdie would like would purportedly be a hinderance....except its modern times and all the roads have tarmac now.