As long as the door remains closed “cold loss” (actually “heat infiltration”) is purely a function of the refrigerator’s insulation capability and the difference in temperature of the room.
There are some tricks you can play to reduce refrigerator operating costs.
Before you do this, get a Kill-a-Watt unit so you can see how much you saved.
1) Move it away from the wall an extra inch so you have better air transfer to the coils.
2) Vacuum and clean the back side.
3) Make sure the fan and area underneath is clean.
4) Keep it full so you lose less cold air when you open it. Use water bottles or cold packs if you have them. they wil also keep it cold longer if you have a power failure.
5) Cover the ice maker hole with insulation on the inside and don’t use it. They are notorious for leaking.
If you have air conditioning, every watt you save by making your fridge run better actually counts a little more than double since your A/C does not have to get rid of the heat.