I guess my 8 is NOT one of those that won't come on after dropping to 0%. I was doing some work for the past 6 hours in another part of the house when I thought I'd check my phone. I thought I had something around 70% when I put it down. When I looked at the phone, it was off. I didn't recall turning it off, so I hit the power button. The phone would not start. I hit the power button again and my heart stopped when I saw a very quick flash of 0% and the phone immediately shut down and would not power up anymore. I tried not to panic, but I plugged her in and she immediately started up! WHEW!!! I still don't recommend trying this but I feel pretty lucky after my accident drain.
No idea why I had such a fast power drain other than a new app I just put on. For those of you with a home camera system (child monitor), is it possible that the monitoring app could have caused this faster than normal drain?