Minn,Simple response to that. Stop sending any outside support to pay for schools, roads, nothing. If they think they can isolate, then cut the state and federal roads off at the edge of their town and lock them in, forever. No commerce across their borders either. They can all try to make homemade microwaves or water pumps, when theirs breaks.
You simply don't get to pick and choose when you will and will not integrate with the rest of us.
To be clear, I'm not advocating less social distancing, I'm just pushing back on the idea that any community can say "mine, mine, mine" with stuff they did not create, let alone pay for, all by themselves.
All I said was that they were barricading their incoming roads.