Simply state you are worried about safety, and only allow one single customer into the store at a time, to be escorted by a private guard/clerk...at the 6 month warning point.
Yep, either make a prepaid reservation or stand in line for half a day to shop….. or drive 30 miles to the next grocery store. Given them the Government type of “service”, line, wait, close store for break, wait, clerk talking to others about personal stuff, wait, dare not complain about lack of service or efficiency, wait……