Place the bacon in a Dutch oven or large stock pot. Turn the heat to medium and cook, stirring occasionally until the bacon is crispy. Remove with a slotted spoon and drain on paper towels and set aside.
Add the cauliflower to the bacon grease and cook, stirring occasionally until starting to brown, about 5 minutes. Add the chicken broth, garlic powder, onion powder, pepper and 1 teaspoon salt. Bring to a boil. Cover the pot, lower the heat, and simmer until the cauliflower is very tender, 20-30 minutes.
Working in batches if necessary, blend the soup until smooth. Return to the pot, add the cream cheese, cheddar cheese, cream, and green chilies. Heat on medium-low until the cheeses are fully melted.
Serve topped with the bacon, extra cheese, and green onions.