In a large bowl, combine the cooked chicken, crumbled bacon, diced avocado, diced tomato, and shredded cheddar cheese.
In a separate small bowl, mix together the mayonnaise, Dijon mustard, lemon juice, garlic powder, salt, and pepper until smooth.
Pour the dressing over the chicken mixture and gently toss until everything is well coated.
Take a lettuce leaf and spoon a generous amount of the chicken mixture onto the center.
Fold the sides of the lettuce leaf over the filling and roll it up to create a wrap.
Repeat with the remaining lettuce leaves and filling.
Serve immediately or chill in the refrigerator for about 30 minutes for a refreshing option.