Add russet potatoes, onion, garlic, chicken broth, salt, black pepper, garlic powder, and onion powder to the slow cooker and stir to combine. Ensure the potatoes are mostly submerged in the broth so they cook evenly.

Cook on Low for 6-8 hours until the potatoes are very tender, or cook on High for 3-4 hours. The soup is ready when you can easily break a potato chunk apart with a spoon.

Use a potato masher to partially mash the soup to your desired consistency, leaving some chunks intact. This creates a thick, creamy body without turning the soup fully smooth.

Stir in cream cheese and heavy cream, then continue stirring until the cream cheese melts completely. Look for the mixture to turn glossy and smooth with no visible cream cheese lumps.

Add shredded cheddar and stir until melted, then taste and adjust seasoning. Stop when the cheese is fully incorporated and the soup looks thick and pourable.

Ladle the potato soup into bowls and top with sour cream, extra cheddar, bacon bits, and green onions. Serve immediately while the cheddar and toppings look fresh and bright.