Do you have a wolf or big cat rescue near you? Sometimes they'll take freshly dead carcasses.
Not aware of anybody in the wolf or big cat rescue business around here, for pretty good reason, given the lack of wolves and big cats in the wild. Not aware of any particular effort to use roadkill either. A year or so ago a deer was killed right in front of me on the road. I called my friend Steve and he came and got it, but that one was freshly killed and it was in winter.