Disclaimer: I have not made hotdog buns.
There's a roll recipe I like that has you put a 3 by 4 grid of them in a 9 by 9. Each roll supports the ones next to it, and the walls support the edge rolls. I think you could do something similar with hotdog buns in a high walled pan, assuming you put the right number per pan, to get the right level of height without needing very wide buns.