Yes it's fine- this is no problem with buns that are healthy- if poorly- depends on the condition- I'd never change a snuffle buns environment quickly like that unless it was impossible not too( I'd keep them in permanently once brought inside). Dental buns tend to be fine in my experience at change ( Put them out the following day), any bun with any kind of infections I'd keep an eye on also ( probably not change the environment- except to bring in and keep in permanently, but generally yes it's fine to bring them indoors and put them out again for just one night like you would after anesthetic for example.