All the big grocery stores here have generators so even without island wide power they’d reopen.
Three days is enough here because at worst I would only need long enough until the airport reopens. Two years ago there was a huge typhoon that hit Saipan. It completely devastated the island. The electrical power was out for months but the airport reopened within 24 hours after the storm moved out. Since my wife is in Hong Kong and we have a flat there I doubt I’d need more than three to five days to catch a flight.
Also, if it isn’t a radiological issue there are mango, coconut, papaya, banana, citrus and breadfruit trees everywhere here. I have all of those except for citrus breadfruit in my yard and they are constantly bearing. After the last typhoon here I picked up 650 pounds of mangoes! Those would, in an emergency feed us for a while. I have fishing tackle and it is only a mile to the beach. It takes some time but a 25 pound skip-jack makes a good meal.
This is not suburbia on the US mainland.
3 days ?
most people routinely have 3 days of food at home.