Adjustable Cardboard Box
Adjustable Cardboard Box is a ultimate solution for people who wants to use one cardboard box in all sizes.
It has the editor script that you can adjust it's size.
The cardboard box prefab has the special script on it. Thus it can change size without damaging it's decals or other elements.
You can add more decal or another elements on it. Or you can modify that script to use on another generic 3d models.