In a large pot over medium heat, cook the chopped bacon until crispy, about 8-10 minutes. Remove the bacon and set aside, leaving some fat in the pot.

Add the finely chopped onion and celery to the bacon fat, cooking until translucent, about 5-7 minutes. Stir in minced garlic and sauté for an additional 30 seconds.

Add 2 tablespoons unsalted butter to the pot and melt. Sprinkle in 1/4 cup all-purpose flour, stirring constantly for 1-2 minutes until golden, forming a roux.

Gradually whisk in 4 cups chicken broth and 1 cup whole milk until smooth. Fold in diced russet potatoes, smoked paprika, garlic powder, kosher salt, and black pepper.

Increase the heat slightly to bring to a gentle simmer. Reduce heat to low and cook for 20-25 minutes, or until potatoes are fork-tender.

For a chunkier soup, lightly mash some of the potatoes. For a smoother texture, use an immersion blender.

Stir in 1 cup shredded sharp cheddar cheese until melted. Add 1/2 cup sour cream and most of the cooked bacon, reserving some to garnish.

Ladle the soup into bowls, garnishing with reserved bacon, extra cheddar, and a sprinkle of green onions. Serve hot.