If it goes longer than 4 months then we're all screwed anyways.
“Basically all we need to ride out a food shortage and/or public shutdown.”
Nice job. Sounds like you’re ready. I have a similar amount. But keep a couple of things in mind:
1) Electricity will be around for a long time, as it is still available throughout China.
2) There will be ‘some’ food, so your 4 month supply may last significantly longer. You’ll just be eating what you want, in whatever quantity you want.