No, a hotdog is not a sandwich
Hotdogs exist in their own category on menus
Look at the "sandwich" section on menus - you won't find hotdogs.
If you look at almost any classic menu, you will find that the hot dog isn't located underneath that particular section. The same goes for a hamburger. Both are just different styles of food, "diner food", that can't be classified as sandwiches. A hot dog is a hot dog, a sandwich is a sandwich. If a hot dog is a sandwich, menus would have to place so many items under that particular section.
Some menus actually DO have hot dogs and hamburgers under their sandwich section on the menus. You can't place all menus into one category, and you also can't use something like that to decide whether or not hot dogs should be considered as sandwiches.
[P1] Menus don't consider hot dogs as sandwiches. [P2] We should not classify them as such, either.
Rejecting the premises
[RP1 - P2] This argument is an appeal to authority. The case could be made that in debating the meaning of words, an appeal to authority is appropriate (descriptivism). But this needs to be spelled out