It depends on the length and area of the nuclear winter, not on bombing each individual. There would be the added genetic destruction through radiation, so it's

It depends on the length and area of the nuclear winter, not on bombing each individual. There would be the added genetic destruction through radiation, so it's not just like surviving Siberia. Also the humans that survived through Greenland had prepared for generations to live in hardship. Those left after any nuclear war certainly won't have been living their lives in nuclear winter world, no matter how good the doomsday peppers think they are.