8 Costumes just isn’t enough. I had a few ideas on a few characters who could wear alternate costumes.
Mr. Incredible
Mr. Incredible could wear his blue and black outfit from the Glory Days section from the start of the film.
Felix
For Felix, I wasn’t thinking of his tuxedo. I was thinking more about the outfit he wore during the 30th anniversary party of his and Ralph’s game.
Calhoun
For Calhoun, she could don the wedding dress from her backstory/the ending of the movie.
Sadness
Sadness’s costume is easy. The participation award.
Kermit
For Kermit, I feel like his Tuxedo would be a good costume for him.
Darkwing Duck
For Darkwing Duck, his civilian attire could serve as his alternate costume.
But eh, these are just some ideas I had. Again, please be kind.