Windows has always not slept well
Why should windows 10 be any different from any other version of windows? I have a full blown laptop that overheats in the bag. My laptop doesn't come back from long periods of sleep, either. It's just windows. Win XP, Win 7 and Win 8 & 8.1 all had the problem.
the thing is completely solid state. It takes, what, 10 seconds to boot up? Save your work, shut it down and save yourself the headache.
If you want a device that reliably sleeps, look to and Android or iOS device.