In a large pot over medium heat, saute the onion in olive oil until soft. Add carrots, potatoes, wine, sugar, and salt and saute 3-4 minutes.
Add 3 1/2 cups corn.
Add enough milk to just cover the ingredients.
Bring to a boil, then reduce the heat and simmer 20 minutes. Remove from heat and puree gently with an immersion blender to desired consistency. If you don’t have an immersion blender, transfer the mixture, in batches, to a regular blender and blend. Return to heat and add the remaining 1/2 cup of corn. Allow to cook an additional 2-3 minutes.