What do people do for groceries in those really small towns?

Town grocery stores existed long before Walmarts and Trader Joe's

I was born on a farm and there were things that we didn't grow or raise and had to buy. One grocery store locally owned and higher prices than you will find at those chain stores or large city stores. People who could would go to a medium size city and stock up on what they knew they'd use for a month and then go to the little local store and buy anything else they ran out of.

Travel many miles to Walmart.

I think they are fine, they know where to go & what to do.. Probably far more resourceful then us "big box store" shoppers!

Dollar General.

I suppose the closest thing to a Walmart around here is 500km away. As well as clothes stores for adults, cinemas, KFC and Vet. We do have a grocery store. Even though the you'll pay 4 times as much for fresh veges as you would in the city.

Take a long drive to a grocery store

Either they go to the local grocery store or travel to the nearest one in a neighbouring town or they grow their own food. The little town I grew up nearby didn't have a grocery chain store but we had a local store that had everything we needed. We also raised our own meat and vegetables.

You can buy anything on Amazon.

Some might have a Safeway