I have a question about potatoes. I want to make duchess mashed potatoes for Christmas Eve. Most recipes call for egg yolks. In my freezer I have some leftover mashed potatoes from thanksgiving that I never baked (potatoes that I boiled, riced, then added butter and cream too). If I thawed these and mixed them with some freshly mashed potatoes, would it still work to incorporate the egg yolks? Any thoughts would be appreciated!! Thanks!