Do you have anything plugged into it at the time? I've heard of people having sleep issues with the 2016's if they have something plugged in, especially monitors. Do you have any weird/special/extra drivers installed?
All that aside, the obvious first steps would be the usual.
Reset the PRAM:
- Shut down your machine.
- Press the power button and then immediately press the command+option+p+r keys.
- Keep these keys pressed down for at least 20 seconds.
- Let go of the keys and let your Mac reboot normally.
And the SMC:
- Shut down the machine.
- Plug in the MagSafe or USB-C power adapter to a power source and to your Mac.
- Using the built-in keyboard, press Shift-Control-Option on the left side of the keyboard, then press the power button at the same time.
- Release all keys, then press the power button again to turn on your Mac
You can also delete the sleepimage, which can sometimes get corrupted. It might not help, but it can't hurt since the system will just recreate the file next time it sleeps.
Open a terminal and type:
sudo rm /var/vm/sleepimage
Someone else may be able to offer more and better advice. I have the same machine as you, running High Sierra since the early betas, for what it's worth, and I'm not having any issues at all with sleep so far.
[doublepost=1506650965][/doublepost]Forgot to add, you can also check /Library/Logs/DiagnosticReports and look for any file ending in .panic, which should be a record of the last kernel panic.
In that file you'll see a line that looks like
BSD process name corresponding to current thread: _______
The _____ will of course be whatever it was that crashed your machine, such as "kernel_task" or "powerd" or whatever. Might help you google for answers if nothing else.