Help? About my genie pig? Cage?

Ok I have a 2ft by 2ft by 2ft by 2ft, and yea i love it i built it, but thing is it can get messy after like 1 - 2 weeks, suppost to. But my grandma wants me to put him in a box because it takes up less space, and room, and easyer to clean, thing is not enough room! I dont know what to do! The size of my cage is human for just one genie pig, now she wants to use a bx smaler? least iin the cage right now she can pop corn! you know makes me upset what you think guys?