In my book I mention that Australia has substantially more arable land per person than any other country.  With 2.14 hectares per capita, it beats Kazakhstan with 1.45 and Canada with 1.25. Every other country is below 1.

71% of Australia’s food is exported, which means it produces 3x the food it needs. Food imports are few and not critical:

But not everything that Australians like to eat is produced here. So we import about 11% of the food and beverages we consume by value.

The imports are mainly processed products (including coffee beans, frozen vegetables, seafood products, and beverages), along with small amounts of out-of-season fresh food.
https://theconversation.com/dont-panic-australia-has-truly-excellent-food-security-136405

So, to reiterate, from Safe Spots where I say Australia is the safest place to be:

Australia has no nuclear power plants, and its exposure to earthquakes and volcanoes is minimal. It has a modern, western culture, and it is unlikely to have many neighbours turn up during a tragedy as it is surrounded by ocean. Population density is quite low, and it has substantially more arable land per person than any other country. Americans and Brits have no trouble fitting in.