stores restock every day; every week. there will not be supply shortages, just things out of stock until they get restocked the next day. For all we know, stores may start having things that are selling out quickly shipped to them in larger quantities.
This isn’t like the potato famine or similar where the actual production was disrupted, or a war or natural disaster where supply chains are disrupted, leading to real shortages. Just people buying in larger quantities than stores have stocked for.
If you can’t get what you need today, it’ll be there tomorrow, etc. While the stock market has crashed, retail stores are seeing their biggest profits in years. They have every incentive to keep restocking and even to respond by stocking in larger quantities during this time.
Supply chains are intact but they can't deal with this level of demand immediately and so there's going to be a period in which there are shortages. How long those shortages last depend not only demand but on other factors, e.g. how many people in the supply chain are directly or indirectly affected by the virus.
But there are diminishing marginal returns.
Check your local retailers today and see if they’re still sold out of toilet paper.