In the door
If the layout allows, then you can install the unit at the door. This is suitable in the case if there is a convenient angle or a flat wall near it. If it is possible to order furniture for the master, then you can always choose the optimal size for your room.
Under the work surface
If the family consists of 2-3 people, then there is no need to buy a large refrigerator. Choose for yourself a low model of about 50 cm. It can be hidden under the countertop, which will save space.
Not in the kitchen
If you want to buy a full-fledged model, but there is not enough room - consider installing it in another room. For example, a closet, an adjacent room or even on a balcony, if it is glazed. But then you should consider the style of the room where it will be located.