when searching for an update on the official Oreo update for the Samsung s8, I came across this, now being one to take a few risks, I quickly downloaded and installed, god only knows what warranty or international peace treaties I may have broken, but its my phone, so if it ended up a parer weight, that's my choice and issue....
https://www.xda-developers.com/how-to-install-android-oreo-on-the-samsung-galaxy-s8-s8-exynos/
(and yes the version number really is G950FXXU1"CRAP" )
Install was a breeze, lost nothing, phone working perfectly, no issues with the reported random reboots, that said, the update in nothing to write home about, in fact unless you go looking, there really is very little cosmetic difference!
of course for the less game, feel free to wait for the NZ specific updates :-)