The cancellation of schools in most states and work-from-home edicts have left many families unfettered by offices or primary residences, free to work wherever they can find Wi-Fi.

The influx has drained local supermarkets, and fueled fear that a continued onslaught could cripple towns with tiny police forces and few hospitals.

“Just try to get chicken,” said Pete Byron, the mayor of Wildwood, N.J. “You can’t get chicken.”

At Red Horse Market, a gourmet food shop in East Hampton, part of Long Island’s East End, some customers are phoning in to ask for personal shoppers or for delivery to their cars, so they don’t have to walk through the store, said Jeff Lange, one of the owners.

At the moment, he said his 30-person staff is too busy to accommodate such requests.

“We had people showing up to buy a lot of meat,” Mr. Lange said, “and there were moments where we had to step in and say, ‘That’s too much.’ There’s no hard line on the meat, for example, but if it seems like more than what is fair, we say so.”

A liquor store in Sag Harbor, another Hamptons town, is selling cases of wine and spirits through a half-opened door.

“It’s like the Fourth of July out here,” said Robin Farnam, a clerk at the store.

The number of known coronavirus cases in the United States continues to grow quickly.

As of Thursday morning, there have been at least 81,578 cases of coronavirus confirmed by lab tests and 1,180 deaths, according to a New York Times database. Close to half are in New York State and most of these are from New York City — an easy drive to some of the wealthiest enclaves in the nation.