Thought I'd let you know I have the same problem with a 2016 15" MacBook Pro with Intel Iris Pro when connected via mini display port to a Samsung 24" 4K. The monitor does have some strange power saving settings like Eco timeout and often the MacBook Pro can't send the monitor to sleep based on the energy prefs and I also find it turning itself on with black screen.
Anyway back to the real problem, after being asleep connected to the monitor and AC and lid shut, say overnight, it will not wake, then opening lid built-in screen is black, force track pad is not powered up. However sometimes the backlight comes on. Hard reboot required. Upon reboot I've sometimes seen the sleep wake failure kernel error shown.
Since the trackpad is dead I doubt QuickRes would work, even if auto login was enabled to make it possible given the key combo doesn't work from lock screen. Well can't remote login either so it definitely has crashed.
The energy pref for 'don't allow sleep when AC connected' does seem to prevent it happening at the desk, however say while lid shut you disconnect the AC and monitor to take the laptop away somewhere, then it won't wake upon opening lid same problem again. And by the way it also happens if the Mac is asleep and then connected to the display, it won't wake up again. So I have to ensure I wake it before connecting the display.
Since the problem happens on a real Mac it's either Intel hardware problem, driver bug, or OS X bug. Since it never happens when only the internal display is being used it means it's external/display port related.