The reason it doesn't happen anymore is that a) surplus + international trade is used to hedge against localized disaster, and b) we've been lucky so far. So sure, we've invented canning and freezing, but we've also invented just-in-time inventory. So unless you stock a season's worth of canned goods, or have someone with a large private farm in your social circles, good luck getting food long-term if a continental-scale food shortage strikes.