If you are transporting potato salad or any other perishable items over a long distance, say to Grandma's house, the beach or a wedding reception, I would put it in a proper cooler with plenty of ice.
The cooler shown here is by Coleman, the manufacturer of my own cooler. It will hold two 2-litre bottles upright. Sorry, that is how manufacturers talk about cooler size, in the size of pop cans and bottles.
I think it is a good size for carrying items like potato salad although they will have to be in a rectangular container, I expect and not a salad bowl. However, my own personal cooler by Coleman is considerably bigger because we use it for camping for a family of four.
Karen in New York says that this 28-quart cooler is a "Great size cooler for a weekend at the cabin. Reliable quality from Coleman...That's why we keep going back to this manufacturer for a product that we KNOW will be effective, efficient, and usable for years."
Coleman has produced a cooler for everyone and for every need. You will likely need to own more than one! However you choose to do it, make sure you keep your potato salad and other perishables cold.
To find this cooler on Amazon, click right here. To see Amazon's complete selection of Coleman coolers which come in a range of sizes, styles and colors click here.