Re: Bottling a REALLY high gravity beer
Why not acquire and use more of the WLP885 yeast? It obviously can handle the higher abv% and you wouldn't risk changing the brews' flavor profile during age evolution.
As for the amount of yeast, most Belgian brewers pitch 1-3 million cells/milliliter of beer for bottle conditioning.
Check out BLAM for more details.
Also, Pierre Rajotte's Belgian Ales has a chapter on bottle condtioning which is very informative.
One more thing, I believe Vinnie Cilurzo and Tomme Arthur both use white wine yeast for bottle conditioning.
I know you have thought of it but I'd probably keg it and call it a day rather than risk a flat and ruined batch of such carefully brewed beer. At least you could counter pressure bottle fill after keg conditioning if you want too.