To make ahead and freeze: Make soup as directed in steps 1 and 2; cool to room temperature. Place in 1-gallon resealable freezer plastic bag. Seal bag. Lay flat and freeze up to 3 months. When ready to use, thaw in refrigerator overnight or until completely thawed. Heat in 3-quart saucepan over medium heat; stir in half-and-half and basil. Continue with step 4.