I actually find it easier to maintain a consistent temperature on the UD, Both cabin and galley! At BA we have a few rogue 744's which seem to have sub-arctic conditions in the galley but the majority of them are alright. Once the main meal service is complete however I do tend to move trolleys around so that only one set of chillers are on at any one time. Also open the ovens after warming them for 5 minutes, that usually warms up the galley in no time!!!