When kept in the refrigerator funeral potatoes will last from 1 to 3 days but it's best to eat the funeral potatoes within a day of refrigerating them for the best taste and freshness.
If you want to keep leftover funeral potatoes you should put them in a freezer safe dish and then cover the dish with some plastic wrap or a lid and freeze the funeral potatoes.
When kept frozen funeral potatoes will last a few months to a year but the longer you keep the funeral potatoes frozen the less fresh they will be.
So it's best to eat the frozen funeral potatoes within a week or month of freezing them.
If I have any leftover funeral potatoes and want to keep them longer than a few days I always freeze them but sometimes we eat the funeral potatoes within the next day or 2 of refrigerating them.