Originally Posted by MaltyHops
So would a good option be to add the Montrachet at fermentation end and wait a few weeks to see how much lower the Montrachet will take it before priming/bottling?
I don't think a few weeks would be necessary, but a few days might help. Just to make sure it doesn't start to attenuate more. That stuff can take wine/cider down below 1.000, so it's very hearty. Plus wine and champagne yeast will eat sugars that ale yeast won't. I know a lot of people like to use wine or champagne yeast for bottling high gravity beers, but I prefer to use a high gravity ale yeast. The ale yeast doesn't seem to be able to attenuate quite as much. Just my opinion.