I’ve spent a reasonable amount of time there. A crude generalisation would be most Italian families eat far less processed and preprepared food, shopping more in local bakeries, greengrocers, delis and butchers. You don’t really panic buy the kind of stuff you use to make a freshly cooked meal every day. Panic buying in your local shops, as opposed to faceless supermarkets, wouldn’t be a good look.
I cook most nights and would it find hard to not need to go shopping every week for milk, eggs, fruit, veg and meat anyway. I reckon three weeks eating through the freezer and cupboard would be as long as we could last, which thankfully is the maximum amount of time any individual needs to isolate in a 2-person household under current UK guidance!