I'm told white grape concentrate will add body, flavor and help w the ABV. I'm in the middle of a WE Island Mist Peach Mango and I started with a lb. of sugar and a liter of concentrate. It bumped my OG to 1.072. Good for 10.5%.
If wine is life; and, life is about the journey (not the destination); the greatest joy in wine is found along the way.