Place tomatoes with their juice in a medium bowl; crush tomatoes well, into small pieces, with a potato masher.
In a 3-quart saucepan, heat oil over medium-low heat. Add onion and celery; cover and cook 10 minutes, stirring occasionally. Stir in tomatoes, broth, wine, sugar and thyme; heat to boiling over high heat. Reduce heat to low; cover and simmer 20 minutes until vegetables are very tender.
Stir in cream and 1/2 cup Stilton; heat through but do not boil. Ladle soup into 6 soup bowls; sprinkle with pepper and remaining Stilton.