Cook bacon in a large pot or Dutch oven over medium 5-6 minutes until crispy; transfer with a slotted spoon to a paper towel.
Brown sausage in bacon drippings 6-8 minutes, breaking up with a wooden spoon; set aside.
Drain all but 1 tablespoon grease; cook onion 3-4 minutes until softened, then garlic 1 more minute.
Add broth, potatoes, and pepper flakes; boil, reduce heat, and simmer 15-20 minutes until potatoes are fork-tender.
Return sausage; stir in cream and return to a gentle simmer.
Add kale; cook 3-5 minutes until wilted and tender and season with salt and pepper.
Serve hot topped with crispy bacon. Flavor improves next day, making it useful for meal prep.