Whisk together 4 cups buttermilk, t 2bsp salt and hot sauce in large bowl or baking dish. Add chicken, turn to coat, cover and refrigerate at least 4 hours or overnight.
Pour remaining 2 cups buttermilk into bowl. Stir in flour, garlic and onion powders, paprika and cayenne in a large bow. Season generously with salt and pepper. Divide between 2 shallow platters.
Drain chicken in colander and pat dry. Dredge pieces a few at a time in one platter of flour mixture, pat off any excess, then dip in buttermilk and allow any excess to drain off. Dredge in the second platter of flour and pat off the excess. Put chicken pieces on wire rack set over a baking sheet.
Pour about 3 inches oil into deep cast iron skillet; oil should not come more than halfway up the sides of the pan. Put skilled over medium high heat and heat oil to 375F.
Add chicken to skillet, 3 or 4 pieces at a time, and fry, turning the pieces occasionally, until evenly golden brown and cooked through, about 20 minutes. Remove from oil with slotted spoon, transfer to rack to drain. Repeat for remaining pieces.
Serve with honey-pink peppercorn sauce.