Expired hot dogs are safe to eat as long as they've been refrigerated or frozen.
If the expired hot dogs smell okay and taste okay then they are safe to eat but if the expired hot dogs smell bad or have a bad taste to them then throw them out.
But hot dogs will keep well past their expiration date as long as they've been frozen since the freezing temperatures in the freezer keeps the bacteria from growing on the hot dogs.
However when hot dogs are just kept refrigerated they can still get bacteria on them if they are in the refrigerator longer than 4 to 5 days.
If you don't plan to eat the hot dogs within 5 days you should freeze the hot dogs to keep them longer.
I buy hot dogs on sale and freeze them in my deep freezer in my basement and they have kept for 2 years before I used them all.