I learned this trick simply by looking at newer RV type refrigerators. The 3-way Dometic fridge in my camper works, but I didnt think the lower side (non freezer) was really cold enough.
In my boat, the freezer section does not have a door. You just put what you want frozen in the area and its circled by the cooling rings. The rest of the box gets cold via induction. My older Dometic has a freezer door.
This last trip to Glamis, I took the freezer door off my Camper fridge, and boy am I happy. The freezer still keeps stuff frozen (I dont k now about freezing stuff from room temp) and the lower part is MUCH colder now. Its so good, I was able to turn it down from 10 to 7 and stuff is still colder down below.
Give it a try for sure. If you dont like it you can always put the little door back on.