Heat a large skillet over medium-high heat, adding thick-cut bacon strips. Cook until crispy and golden, about 8-10 minutes. Transfer to paper towels to drain excess grease, then crumble into smaller pieces.

In a Dutch oven, combine the cooked shredded chicken, condensed chicken soup, chicken stock, and whole milk. Stir in softened cream cheese along with chopped celery and sliced carrots. Add the dry ranch dressing mix and mix well until smooth.

Bring the mixture to a gentle boil over medium-high heat, then reduce the heat to medium-low. Allow it to simmer uncovered for 20-25 minutes, stirring occasionally.

Once the vegetables are tender, stir in the uncooked pasta along with crumbled bacon and shredded cheddar cheese. Simmer until the pasta is cooked al dente, about 5-7 minutes.

Ladle the warm soup into bowls, topping each serving with crumbled bacon if desired. Serve immediately.