Nah you don’t need 2000 calories a day. You need that to be healthy. We’re talking about survival here.
The fastest way to destroy the enemy today is to cripple their economic centres. Every major city in the country will be a smoldering crate. And the ports will be turned into 2 smoldering craters. Every major town probably has at least one weapons factory somewhere. It’d reasonably only take 20-40 missiles to wipe most of this country off the face of the map. Hopefully you’re right about fallout.
Either way I think I’ll do ok if we survive the initial shit. Can’t say the same for everyone but with some effort I can also help local people get the same thing up and running. There’ll be no government left so we’ll be on our own.