Potatoes don’t always freeze well, but I have had success with a couple of methods. This one is taken from the 30-day Freezer Gourmet for make-ahead mashed potatoes.
Make Ahead Mashed Potatoes
5 lb bag of potatoes
4 oz. light cream cheese
2 T. butter
Paprika, to taste
Peel and dice potatoes and cook until fork tender. Mash in a bowl with cream cheese, butter and egg. Spread mixture into two 8×8 baking dishes and sprinkle with paprika (I line the pans with waxed paper, freeze until solid and then pull the frozen potato casserole out and wrap in heavy duty foil – then I don’t have my pans hiding in my freezer somewhere and the packets are ready to unwrap into my pan when I’m ready to re-heat).
Defrost in fridge. Cook at 350 for about 35 minutes or until heated through.
I’ve also had a lot of luck freezing soups with pureed potatoes, so long as the soup has another main ingredient like cheese or broccoli. Unfortunately, potatoes seems to need some fat to store well in the freezer, so these are not the healthiest options.
Hope this helps!