Sauté bacon in a large stockpot until crisp; remove from pan, drain on paper towels and crumble. Remove all but 1 tbsp (15 mL) bacon grease from pot; add onion and sauté over medium heat until browned.
Add broth, squash, pears and celery to pot. Bring to a boil; reduce heat and simmer, covered, for 30 minutes.
Let cool slightly, then with an immersion blender or in a blender or food processor, purée mixture until smooth. Return back to pot and add herbs and bacon. Simmer for 10 minutes more. Stir in half-and-half and season to taste with salt and pepper. Ladle into bowls and sprinkle with chopped fresh thyme.