I made it like suggested in the comments with less of the soup mix, one can of cream of mushroom soup, and half the called for onions. The flavor was good but it turned out to be pretty dry, even though I cooked it for less time than called for. I probably could have added the 2nd can of mushroom soup.
I doubled the recipe and it worked out great! Left the skins on and left them pretty chunky due to the lack of a potato masher in my kitchen.