I'm curious on what yeast you are using for a 14% barleywine.
My go to ale yeast, S0-4. It will easily hit 11%. Might augment this with some champagne or wine yeast to get us over the top.
No champagne or wine yeast...I have not had good results doing that. Your results may be different. Just make a good wort and pitch a lot of yeast.
IIRC wine and champagne yeasts don't do well fermenting maltose and maltotriose. They work on simple sugars. Priming a high abv beer with simple sugar? Champagne yeast will work for that.
That's what I recall, too, and my experience seems to bear that out