I think it will vary depending on areas. Some places that have seen a lot of cases may be able to return to normal earlier than places that are just now starting to be hit.
FWIW
Walmart announced today that all their locations are shifting hours to 6am-11pm so they can use the overnight hours to restock and clean. Other grocerers have shortened their hours as well.
My best friend works at Target in a college town near me. Her comment on FB today was "Put in an 11hour day of OT to help my team and the store get throught the madness and today's truck"
So stores seem to be really trying to work on restocking the shelves--restocked shelves are def. a step in the direction of normalcy. Restocked shelves might also help reduce the amount of people who feel that psychological pull to purchase items that are on low supply because they won't be so low in supply anymore "well if other people are buying it maybe I need to buy it". Dunno how many that will work with though lol.