We tell the stores that carry them not to keep them over a month. Once they are out of our hands, we can't control the environment they are in, (heat, humidity, stored next to something with orders like onions...). Thus the 1 month expiration suggestion.
They are pretty stable and if kept in a sealed container, should last well beyond a month... but better to consume early. They are not intended for food storage.
The honey on the other hand can probably last for centuries... And if you are going to keep it for centuries, I would recommend storing it in glass, not plastic or metal.
I need to find that old bag of caramels and give it a taste... they got to be three years old by now...
We make new batches 2 to 3 times a week, so they are usually 1-2 days old when we send them out.
This week we have made 3000 honey caramels. Much busier week than normal!