Can you heat up a pudding mixture with cool whip?
I've never tried heating cool whip, but your only option is to try. Instant pudding will set without heating it, but if you don't cook a heat-set pudding mix it will stay runny, so there's 3 possible outcomes:


Don't heat it - ruined
Heat it and the cool whip goes wrong - ruined
Heat it and it works - success


You lose little by trying.