Most (not all, but most) rural cops I've known are not that type. They would feel a whole lot safer with the armed half of the county on their side than trying to protect their homes on their own. A rural area that generates its own food can hold out until order is reestablished. Without the people, it cannot take care of the livestock, dairy cows, the crops, or self-defense. Only a fool would get excited about his jackboots when his family's safety depends on the community. Most rural cops are not fools.
I think the chances are good the authorities will end up searching for hoarders.
A County Sheriff in Western ND once said, "I'm not afraid of some gang banger with an AK-47 spraying and praying. I'd be more afraid of a pissed off farmer with a deer rifle, because he is going to hit what he shoots at the first time."
That statement was in reply to a question about the Assault Weapons Ban when Clinton was in office. I supported him for Sheriff, have never regretted that, and he has been Sheriff since.