Alright, I got an idea, though it does involve Gren doing (Well, did) some heavy renovations to their dormitory. Gren's computer is huge, and as sturdy as him. He could have arranged to replace one of the bottom bunks with his rig, while also setting up a bunk above his computer. Don't worry about the weight damaging his computer; it can handle it. Now that just means someone else is sleeping on the top bunk. Gren never slept in a bed yet, and even if he did I doubt anyone would want his 300lb ass hanging over them.

A quirk about Gren that IC his team likely already know but might have just now been revealed, but he prefers to sleep sitting. Reclining in a chair perhaps, most still sitting.