Don't know if this would work with every potato salad, but it's worth a shot.
My nephew-in-law made a sort of German potato salad with onions, oil and vinegar. There was a lot left over so I thought I'd give it shot making potato soup.
I sauteed more onions in bacon grease, added a couple sliced, peeled raw potatoes and a pint of half and half.
I let this simmer for a while until the raw potatoes were cooked, then added the leftover salad and blended it all with an immersion blender.
I added milk to make it the right consistency, then seasoned it with salt and pepper and a few slices of crumbled bacon.
It turned out great and my NIL is loving it. Give it a shot with your version of potato salad and let me know how it turns out.