my grandparents did that years ago making homemade kielbasa... she didn't know he had added the salt so she did, and then I think he forgot that he had so he put in even more! it was the worst stuff imaginable but my parents made us sit there and eat every bite on our plates... and told us to put more ketchup and mustard on to hide the salty taste - so more salt laden product on top of the already salty meat! it's too bad we couldn't have just added more meat... LOL...
but yes, you definitely could make some more potatoes (no more salt) and mash them in to cut down on the saltiness...