You can try to turn off your refrigerator from time to time but the biggest problem you are going to run into will have to do with remembering to turn it back on before it gets too warm and the food spoils.
Honestly it isn't something we would recommend. Instead you can turn the temp down a bit and make sure that it is always full with either food or gallon sized full water bottles to maintain the temperature inside even after opening the the door.
Just be really careful with lowering the temperature too much because the food can spoil. Instead try to keep it at the temperature that the instruction manual suggests.