In a small bowl, whisk together 1 1/2 cups buffalo sauce, 1/4 cup melted unsalted butter, and 4 minced garlic cloves until smooth.
Place 4 pounds of bone-in, skin-on chicken wings into a 6-quart slow cooker.
Pour the sauce mixture over the wings and toss gently to coat all pieces evenly.
Cover and cook on low for 3 hours, or until the wings reach an internal temperature of 165°F.
While the wings cook, line a baking sheet with foil and lightly spray or brush with olive oil.
When the wings reach 165°F, remove them from the slow cooker and arrange in a single layer on the prepared baking sheet.
Preheat the oven broiler to high. Brush wings with additional buffalo sauce, broil 4–5 minutes until lightly browned, flip, brush the other side, and broil another 4–5 minutes.
Serve hot with carrot and celery sticks, extra buffalo sauce, and ranch or blue cheese dressing.