I’d be a bit careful of some of those suggested drinking windows if I were you. They are given in all good faith, but they are guesses.
The great bugbear you will need to navigate around is the fact that red Burgs. can close down hard very suddenly. A bottle opened in this state is heartbreakingly inaccessible if totally closed, or just a sad glimpse of what might be if partially closed. So it’s not good news that some 2012s are indeed closed or closing.
So those guesses may be right, or not. But what I would recommend, if you have only the one bottle, is to try to keep on top of things through asking around or reading up. There’s a lot of information on Cellar Tracker, but lots of people don’t have much of a clue about this sort of thing. If you can focus on a few names there that do seem to have that expertise, that might be possible.
More specialist forums are another option. Well worth asking here, and over on the Wine Pages forum. Not an exclusive list of course - there are more specialist paid-for services such as Bill Nanson’s Big Red Diary, etc. etc.
But in general, you need to bear in mind the fact that Grands Crus (such as yours) often take longer to come around than lesser ones, and the winemaking style of the house also has an influence.
I hope I haven’t put you off! It may of course be lovely right now for all I know. Just ignore any comments that it’s over the hill. Everyone says that about closed-down burgundies. A true over-the-hill burgundy tastes faded out and somewhat oxidised, which is different.