The only thing I'd add is, use them the following day.
Maybe it's just the type of potatoes we find down here, but after about 36 hours, something cruddy happens to the flavour. Can't describe it, but it's not pleasant.
Curious if any other 'empty nesters' found potatoes (especially mashed) the hardest food to adjust quantities to two people? After the kids left, it took years to look at two potatoes and realize that would be enough! What a challenge to find all kinds of things to do with leftovers... ;)