The recipe is just a minor adaptation of one we found on Epicurious:
Changes we made to prepare:
Roast cubes of butternut squash tossed with olive oil under the broiler until soft, gives this soup a much better flavor
Fresh chicken stock instead of broth
Omit the water and use good quality white wine instead in the step where you add the squash, etc.
I found no reason to add anything to thin the soup, it's the perfect consistency (in my opinion) with the addition of the creme fraiche.
To serve, I drizzled more creme fraiche from a squeeze bottle and garnished with the bits of crumbled bacon.
This soup is absolutely wonderful.