Don't over-mash: about 8 gentle mashes is plenty. Use block-style cream cheese, not the whipped tub, so the soup stays silky. Always add the dairy at the end to avoid curdling. Let the soup rest on warm for 10 minutes before serving so it thickens to a spoon-coating consistency. Fridge: store in airtight containers for up to 4 days. Freezer: freeze single-serving containers for up to 3 months; potatoes soften slightly after thawing. Reheat gently on the stovetop with a splash of broth or milk.