12.873% eh? Five significant figures is pretty impressive with a home hydrometer. I think my high school chemistry teacher is turning over in his grave.
That yeast can go as high as 18% (or more) so you might be able to get it going again with some nutrient and energizer with a bit of a stir to get the old yeast on the bottom moving again. Or if you wanted you could add the nutrient/energizer to the wine and make a good foamy, frothy starter with the wine and some fresh yeast and pitch it in.
I am by no means the a model of sanitation when I do wine. So I'd say just use a turkey baster to get about a cup or two or wine out of your primary. Add a quarter teaspoon of energizer and nutrient. Add a packet of yeast, put in a smallish plastic container or jar and shake like crazy. The yeast will use up the oxygen you add at this point so don't worry about it messing up the wine. Let it sit in a warm place until the yeast has really frothed up. Could be as short as 30 min or as long as a couple hours. My method for mixing in the wine would be to suck it up in the turkey baster, and inject it into the wine without bubbling. If you keep it below the surface of the wine you can just keep squeezing and unsqueezing the bulb, without bubbling, and you'll mix and agitate the wine & yeast pretty well without adding a significant amount of oxygen.
or if you're happy with a sweet ~12%-13% wine let it be.