Cook bacon in a wide 6- to 8-quart heavy pot over moderate heat, stirring frequently, until crisp, about 5 minutes. Transfer with a slotted spoon to paper towels to drain, then add onion, carrots, celery, and bell pepper to bacon fat and cook, stirring, until onion is softened, 8 to 10 minutes.
Add all potatoes, broth, and thyme and simmer, covered, until potatoes are just tender, about 15 minutes. Add corn and cream and simmer, uncovered, 10 minutes. Add sea salt and pepper, then stir in bacon.