[Request]: Winter raiding army events for the north

From Cregan Stark's winter army, to the greybeards of the hill clans under Stannis, to Jon and Alys's Karstark's discussion of old men going "hunting" in the winter we are repeatedly told that the North has a tradition of winter armies where young men and greybeards will go off to fight and die when food is scarce in the winter (apparently volume I of Fire and Blood will also discuss this as a longstanding northern tradition that caused tension between the Starks and Targs when Aegon and his successors prevented what was essentially the way the north dealt with insufficient resources in winter), is there any chance that someone could make a mechanic not unlike the ironborn reaver recruits where you get a free upkeep army in severe winter it you are the north but you need to use it to raid/attack the south or you suffer penalties?