New Zealand is a special case where it may be feasible to isolate yourself from the rest of the world and reach zero cases. With that said, it remains to be seen that it is possible to maintain zero community spread over the long term, and whether the economic impact of isolating yourself from the rest of the world is worth it.

We aren't economically isolated from the rest of the world. We're still exporting and importing. Exports in some industries are higher than ever. We're still bringing in workers in certain key roles. NZers can leave (though they'll probably need to pay for quarantine when they get back). The main things that are suspended are international student and tourist arrivals, and when the flood of NZers returning home abates, we'll probably be bringing them in through the quarantine system.

We're only isolating human traffic. We're not isolating exports or imports of goods.

What was the death rate and high-severity rate of infection for each of those clusters? The reason people focus specifically on the retirement homes is that it tends to have the most dire outcomes.