Early morning on a weekday is a very good plan.
I have been doing the Walmart senior hour (every Tuesday at 6AM). The store is empty, decently stocked, and the workers are very friendly (N CT).
I was considering doing the BJ’s senior hour at a local store and my son told me not to. According to the local community chat room, the place is PACKED for that hour.
He said to go later. I did and it wasn’t all that crowded.