Well it's worth knowing that Creme Fraiche works just as well in most recipes, I use it all the time instead of heavy cream, especially the low fat creme fraiche. The reason for doing so is the calories are way lower & the taste is just as good. I think you'd still have to go to the store though.
Here's a link that might help:
yeo valley low fat creme fraiche

Had to type it hyperlink wouldn't work