Idle, I'd say you'd get around 35-40C. Maybe reach up to 50-55C under load with the stock cooler.
It's been a while since I read about this stuff but I think they don't become unstable until they're a fair bit above 75C, so I should think auto-shutdown would be around here. I personally wouldn't run one over 60C.
Sorry I can't be of more help but I hope this is of some help. Maybe someone would just confirm what I've just said?
Matt. I