I have a 44sqm apartment with 2 adults, an infant and a cat, and we've managed to fit a month's worth of supplies in a single wardrobe. I don't think space is a problem (weight is, OTOH).
Suddenly stocking to up to 6 months of everything? That's hoarding. Building a month's worth? That's a minimum if you want to stay safe in case you and your family get quarantined, and your normal buffer should be around that anyway, regardless of the pandemic.
Indeed FEMA is now asking that folks only buy a weeks worth of groceries: https://www.mercurynews.com/2020/03/23/coronavirus-new-guide...
Over here in Germany the recommendation has always been to have supplies for 10-14 days at home. Seems like a more reasonable number than a months worth - especially for city dwellers.
> the recommendation has always been to have supplies for 10-14 days at home. Seems like a more reasonable number than a months worth - especially for city dwellers.
That's a nice recommendation for a calm time, but a bit short for the pandemic. If you get quarantined, you need to stay put for 14-21 days. Add a bit of padding to account for undersupplied stores (and to add a margin for error), and you arrive at 1 month's worth.
(The truth is, JIT supply chains simply aren't designed to survive events like a global pandemic. They're control systems overtuned to extract the last bits of efficiency from trade, and fall into bad oscillations when disruptions happen. As we can see today.)