Again, this is dramatically overestimating the initial effects of a nuclear blasts. There will be no major wildfires from nuclear war, for the simple reasons that a.) you don't aim a nuke at the wilderness and b.) the blast wave of a nuclear explosion tends to put out the fires that the thermal pulse ignites. Nukes have specific strategic purposes: the vast majority of them will be aimed at U.S. missile silos, airports or airbases with long runways, ports, refineries, and military shipyards. Those left over will likely be aimed at areas of high population density, specifically the downtown cores of cities.

It's not 1945 anymore, when there was a sharp divide between urban areas and rural areas. The majority of the U.S. population lives in suburbs, and many only go into cities for cultural events. The suburbs are already wired into the U.S. logistic network - that's where are Walmarts and Amazon warehouses are - and are decentralized enough that they're not likely to get taken out by an initial strike.

Coronavirus (particularly Omicron) was much more devastating to our logistic network than nuclear war would be, because it affected essentially all truckers and port workers at once.

I'd encourage you to read the pamphlet; it's put out by scientists whose full-time job was to plan for the continuation American society in the aftermath of a nuclear war.