It’s been bugging me something awful. I may have read it an a “Year’s Best” annual anthology… but then again maybe not.
Anyway, the plot as I recall it:
The world is enveloped in a nuclear winter. This woman seems to be the only woman alive. She drives around in an ice tractor looking for people. But she finds some aliens instead. They seem suprised to see her but are really nice to her. Eventually it comes out that their ship was mistaken for an incoming Nuclear missile, causing both US and Russian to open fire in “retaliation,” thus wiping out all life as we know it on Earth. The aliens are awfully sad and embarassed about this chain of events. Eventually, the woman gets tired of hanging with the aliens and decides to drive acros the Atlantic to Europe. She freezes to death before making the crossing.
Ringing any bells?