Recently finished playing (for nostalgia's sake) the AH game Cuban Missile Crisis: The Aftermath and its somewhat abbreviated, cobbled-together sequel Ice Crusade, and got to wondering what the world might realistically look like in the wake of a nuclear Third World War resulting from the CMC. Ice Crusade has the surviving powers basically relocating to the Southern Hemisphere (as this map shows), overrunning and colonizing the nations and colonies that still existed in the 1960s, while the Northern Hemisphere becomes frozen in nuclear winter, abandoned except for salvage operations and sparse enclaves of survivors. Based on the strategies, arsenals, and politics of the time, and presuming all-out attacks by every nation involved, what are the odds of anything like this scenario actually happening? If not, what outcome is most plausible?