In large stockpot or dutch oven, cook the bacon pieces. Start with medium high heat and continually reduce the heat as the bacon sizzles and the grease bubbles, while occasionally stirring. Remove bacon with a slotted spoon and transfer to a paper towel lined plate. Discard all of the bacon grease except the bottom layer in the pot that holds all the flavor.
Over medium heat in the same pot, melt the butter. Sprinkle the flour on top, stir, and allow to cook while stirring frequently, until mixture is fragrant, about 5 minutes.
Add garlic powder, milk, and chicken broth. Stir well to combine and scrape the bottom of the pan. Mixture should resemble a very thin gravy.
Remove the skins from your baked potatoes and roughly chop. Add them to your soup, along with the green onions, cheddar, and sour cream. Allow to heat through. Add salt and pepper to taste.
Serve with cooked bacon pieces.