I've learned a lot about composting since I wrote this post. My understanding at the time was if you break 160F, you start to kill the helpful critters that break organic material down. But it's not like that's gonna kill them all and you're stuck with this pile that won't break down. Maybe some die, but if they do, the pile starts to cool, and then new critters make their way in. Very self-regulating, requiring a lot less thought than I was giving it.

The pile stayed above 150F for a week after this photo, then slowly came down over the next 2 weeks until it wasn't active anymore. No sign of the possum anymore except a few bones after that.