Hi ! Which characters fit in your outfit Catsuit? I tried with DOA characters and that's work but for the other I don't know. And same for your christmas bodysuit.
Officially, only the ones they're built for.
Most of my characters have bespoke bodies. Maya's outfits won't work on Gaige, Jill's won't work on Claire, etc. The Curvy and DOAFantasy characters are the only ones with standardized bodies, explicitly to allow outfit swapping between them. But even that is only within the same standard - Curvy outfits only work on Curvy models, DOAFantasy outfits only work on DOAFantasy bodies.
Unofficially...
There are people out there who are pretty crazy good at hacking outfits together, using a combination of scaling individual bones and pulling them around to get them to conform to other character bodies. I don't officially support this, and I don't offer any advice or guidance on how to do it. But if you can pull it off, then you have my blessing and you have my respect. I don't have the patience for that, and I envy those that do.