@john_b and the UK doesn't get a mention because most of our hotdogs are rubbish.
However, @Mauve_matelot works at Cap'n Jasper's in Plymouth where this is a thing.
Half a yard (yes. 18"!) of hotdog with lettuce, sliced tomato, fried onions and a wide selection of help-yourself relishes. 😋😋
OH DEAR. THIS POST WAS SET TO SELF-DETONATE 💣 💥 🔥
Ą̷͇̀l̵̩̓̕l̸̩͘ ̸̭̪̈́ť̷̝̍̆h̶̡̛̰̯̏͌a̷͕̞͋̂t̵̩͙͑̈́͝'̵̛̍́ͅͅş̴̬̱͝ ̷̗̊͠l̵͚̕͠ē̸̻͓̐͝f̷̧͙̀̑͝t̶͓̓͊̚ ̶̜̱̓͌́a̴͉͊r̶̡̩͛̀é̵̦̞͕ ̶̮̾ṫ̷̡͈̍ḧ̸̛͍́̊e̴̫̅ş̶̥̰̓e̴̟̪͌͂̇ ̷̞̅͊̚h̷̰͕͈͂e̶̡̹̜̚ŗ̸̗͈̾̇e̴̩̍͐ ̷̪͉̩̀a̵̡̱̐͑͝s̴͎͖̈́h̸͈͌́͜e̴͕̝̐̌ś̶͓̆ͅ.̵̩̉ ̵̱͊͑̀