If it is global nuclear war as predicted there is no way it won't affect us. I can't see us not being involved and being targeted. Even if we aren't targeted who knows what the detonation of multiple nuclear warheads will do. That might cause another ice age. It would definitely affect our climate and not in a beneficial way.
Yes there is no winner in a global thermo nuclear war and it can make a nice nuclear induced winter for a few years. There will be some warming but it will not be a good thing to be north of I 70 in my opinion. This is why I would be heading towards the Ozarks. It does not mater who launches first everyone will launch. This is why I think this guy is not totally right. I do not think we will see this happen in May.