IMHO, there would be no winners from an all out nuclear war, such as was feared in the past.
However I do not foresee a large scale nuclear war with NK. More likely is that the dear leader will launch a single weapon or at the very worst a handful of weapons against the USA or allies. Shortly afterwards I expect that NK will be attacked with devastating force and will effectively cease to exist.
In such a case one could reasonably state that NK had lost and that the USA had won.

An attack on the USA with even a single nuclear weapon could kill millions, or put in more optimistic terms, tens of millions would survive.
The disruption to utility services, government, and food or fuel supply could well be national, hence the need for preparations.
If you are too close to the bomb, then there is almost no hope of survival, but for millions a bit further away, survival might depend on what preps they had made.