This War of Mine is exactly what you're looking for. It's a game where you and your group have to survive in a dilapidated building by foraging a war-ravaged town for supplies and food. There are a few abandoned places you can safely loot at first, but it won't be long before you have to start snatching supplies from other NPC survivors.
Have you checked out This War of Mine? Definitely not a wargame in the traditional sense, but tries to portray the struggles of the civilian population in a war zone.