Winter everytime for me. When i think Ostfront, i think snow and cold...bbrrrrr.
The winter fighting and weather in APOS is stunning and atmospheric
Be interesting to see a properly done Russian front mud fest (rasputitsa) too, as you read about it so often in eastern front accounts and how it affects operations and mobility.
I would love to see a full Operation Typhoon and the Red army winter counter attack done by Graviteam, that would be fantastic.