I'd try and get my hands on some Wyeast #4347.
YEAST STRAIN: 4347 | Eau de Vie™
A very good choice for alcohol tolerance and stuck fermentations. Produces a very clean, dry profile, low ester formation and other volatile aromatics.
Temperature Range: 65-80°F, 18-27°C
Alcohol Tolerance: 21% ABV
Eau de Vie, Grappa/Marc/Bagaceira, Rum, Scotch, Vodka, Whiskey
It'll only get you to ~20% ABV, but you're half way there without any distillation.