When I bought a fridge for my camper I realized why nobody who cares about power usage has a common standing fridge. Every time you open the door the cool air falls out, it sucks in the warm room air and has to start over again.

While "camping coolers" just keep the cold air inside.

My fridge doesn't cool when the door is opened, not even sure if slightly longer opening times make a huge difference when the complete air is exchanged in seconds anyway.