This is the latest version of a cage idea I've been thinking about and refining for a year or so. I've built some other cages similar to this that are posted on the Caging forum.
But I thought this cage might be of most interest to M. viridis enthusiasts so I'm posting it here.
This cage is a 50 gallon Sterilite tote. The front of the cage is a face frame made from pine. The hinged acrlyic door is recessed into another frame made from 1/4" pine.
The back of the face frame is sealed with epoxy and contact paper. The cage was submerged under water for a day during a flood (no animals in the cage, fortunately) and the epoxy held up perfectly. The front of the face frame is sealed with water-based Polyurethane only and it did suffer a bit of damage.
The top of the cage was routed out and a screen was attached with rivets and hot glue.
Commenting on the durability of the cage, I've had other cages of a similar design in use for over a year now and they're still fine. Some are even heavily laden with large water bowls and rocks.
The area where the face frame and box attach is bonded with Vulkem, an extremely strong polyurethane caulk. It is further supported with dozens of 3/4" sheet metal screws.
I was able to put my 40 lb. nephew in this cage and carry it around by the face frame. The whole unit only flexed slightly. I would not attempt a similar test with most of the commercially available plastic cages. I like my nephew too much 
My nephew was also able to stand on the screen top. The screen would have failed before the rivet and hot glue bond.
I no longer keep M. viridis but feel this cage idea could be useful for this species. I've found a 55 gallon tote similar to this that I think would be perfect for GTP's.
The new box I found, if oriented horizontally rather than vertically, would have dimenions of about 28" x 23" x 18". Obviously the height would vary from front to back due to the "stack and nest" nature of these boxes.
For GTP's I assume most would not use the screen but rather utilize another ventilation source.
Sorry for the condition of the cage in these pictures. The cage fell off of a shelf during the flood and was scratched up. Also, shortly before I took these pictures a friend of mine had a Corucia zebrata born and put mother and baby in this cage for temporary separation. They messed it up pretty good with all of their initial exploration.
