European LG G6 expected to receive Android 8.0 Oreo in Q2 20185
If you've purchased your LG G6 in the United States or Europe, you'll have to wait even longer. According to LG Italy, LG G6 is supposed to be updated to Android Oreo within the first half of 2018, which means the update might arrive by June.
However, the Twitter handle of LG Italy narrows down the time-frame a bit by saying that the release of Android 8.0 Oreo for LG G6 is planned for the second quarter of 2018. Basically, this means that you'll have to wait until April / May for Android Oreo, but only if you're based in Europe.
As far as the US version goes, we have absolutely no idea when the update will hit the LG G6. It might be released after the European model or at the same, but it's hard to believe it will go live before Q2 2018.