I was of the impression that Prions are notoriously impervious to heat. They were said to withstand typical disinfecting protocols using an autoclave (250°F for 15-20min). Quick source:
> To destroy a prion it must be denatured to the point that it can no longer cause normal proteins to misfold. Sustained heat for several hours at extremely high temperatures (900°F and above) will reliably destroy a prion.
Autoclaves are meant to destroy living material while preserving what's being sanitized, while cremation intends to destroy everything and preserve nothing. For that reason, there's a difference in both temperature and exposure times.
I’m not sure how real of a concern this is as deer with CWD die and decompose and I’m not aware of any transmission in this way.