Unless you plan on two UTH or piece of heat tape and 2 thermostats, one on the cool side one on the hot side you will have to heat the room.
In the winter I keep my animals at 75/76 cool side and 88 warm side and the only way to achieve this type of temps on the cool side it to keep the room at 75/76 with a oiled filled heater (obviously I do not want my entire house that warm)