Make a refrigerator that consists of several horizontal draws, kind of like a clothes dresser. This would keep the cold air in better when you open it because the cold air would attempt to go down, but is stuck in the drawer, so it can’t pour out the bottom like in a normal fridge. It would also only expose a small amount to the fridge to heat, so when you open it, at worst you’re only letting out about a fifth of the cold air. Air could circulate between drawers through the rear of each, allowing for one cooling unit, and each could be sealed off pretty simply when they open.
This design would also make it easier to clean (take out one drawer at a time without needing to let the whole thing warm up). It would also help eliminate the waste of having empty space at the back of shelves, and letting cold air out as you try to dig to the back of a shelf looking for something.
You could also then adapt the idea so that the fridge could be more horizontal that vertical (maybe 6 feet wide with 3 columns of drawers, and a couple of feet tall) so you wouldn’t need to bend down to get to the bottom, or stand on your tip toes to see the back of the top shelf. This would take up some valuable counter level space in the kitchen (or could be just below counter level, as the food would be in drawers that you would still want to look down into), but the fridge is easily the most accessed part of any kitchen (except maybe the sink), so I think it justifies the space it would take.
It would also keep kids and pets from attempting to climb into the fridge every time you open it.