We have 2 refrigerators, one that is the official fridge in the kitchen and the other one is the backup in the terrace. They are both medium in size. When the fridge in kitchen couldn’t handle the load, we turn on the one in the terrace. Friends have advised us to buy a bigger fridge but come to think of it, why the need for a big one when we have 2 already? In terms of electric consumption, it’s obvious that our 2 refrigerators are economical than one big fridge.
I am not sure that the two smaller refrigerators would consume less energy than a large one. I have compared smaller vs larger refrigerator suggested energy consumption and while the bigger would be more than the smaller, the combined smaller nits would probably outstrip the larger units consumption, therefore, I should think that it would be wiser to have one larger unit as opposed to two smaller ones.
My parents have two small ones as it's better for space and they can use one for everyday use, and the other is for excess. It works for them, plus if one breaks down or needs cleaning then there is a spare back up. Recently I changed them both and it is handy to have two. The problem with a large one is sometimes you can't find what you want, and then that goes off and is wasted.
I'm good with one medium size refrigerator because I only store meat or food for a maximum of 3 or 4 days and only buy what we intend to cook or consume so there's practically no leftover to store. We don't even store leftover food after a party because we give them away to guests. I'm fine with one unit and I'm not thinking about buying another unit unless my current unit is showing signs of breaking down after years of use in which case it will be better to have one as a backup.