Russia is loving in shambles after the cold war. If they get involved, they will basically fall apart.
Also, the missiles that NK has, if they hit Times Square, won't reach Central Park, blast radius wise. Fallout wise is a different story. I'm glad that I live far away from the major cities. We won't suffer the blast or fallout too badly, and we can always rebuild from a agricultural standpoint. Also the black rain that comes from fallout allows plant regrowth for some odd reason. So unless nuclear winter hits, we will still be alive.