Preheat oven to 400 degrees or prepare grill. In a saucepan, combine lemon, orange, ginger, sugar, and bay leaf with one cup of water. Bring to a boil stirring to dissolve the sugar. Reduce heat and boil uncovered until syrupy, about 10-15 minutes. Stir in cranberries and remove from heat and let cool.
Rub venison with olive oil, 1/2 teaspoon of salt, garlic powder, pepper, and chopped juniper berries, pressing seasonings into the meat. Set the loin on a roasting rack in a roasting pan and roast until rare or medium rare; 135 degrees on an instant reading meat thermometer (about 25-30 minutes). Cover venison with foil and let it rest for 10-15 minutes before carving.
Meanwhile remove and discard the bay leaf, lemon, orange, and ginger from the cranberries. In a food processor, puree half the cranberries and liquid until smooth. In a sauce pan, boil the wine until reduced to 1/2 cup. Add the stock or broth and bring to a boil. Add the cranberry puree. Reduce the heat and simmer uncovered until slightly thickened, about 10 minutes. Remove from the heat. Add the remaining whole cranberries to the sauce with additional pinch of salt and pepper. And chopped juniper berries. Swirl in the cold butter. Slice the venison about 1/4-inch thick. Reheat the sauce and stir in any juices from the venison. Spoon some sauce onto serving plates, place 2-3 slices of venison on the place and spoon over more sauce.
Pair with Frederick Cellars Cabernet Sauvignon.