The problem you're referring to (if I'm not mistaken) has to do with suspend to RAM. So unless you suspended the NUC and it did not wake up you are probably experiencing a different problem. But you can always try to remove the CMOS battery and see if that helps. I think I've read somewhere that this does not void your warranty, but better check back with Intel.
Anyway, I can tell you that freezing every now and then is definitely not normal with Linux. Granted 14.04 is pretty old (older than the Broadwell generation aou're running it on), but even there it should still work if you use a newer kernel. I'm using Arch which is a rolling release distribution and so has alwayws very current software (and bugs;) and I have never experienced a freeze with my NUC5i3.
This message was posted on behalf of Intel Corporation
We have seen a random issue with the NUCs while running Linux operating systems. They are not waking up after sleep mode or hibernation.
Lokutos provides with the workaround on this issue (post 1). Intel is still investigating the problem.