Tegu Enclosure

[John1982]

Honestly, scrap everything your thinking and do a bit more research. With the exception of diet, theses guys have the same caging requirements as savanna monitors, large sealed environment with a good deep substrate for burrowing. You'll want to have at least 8×4×4, with around 2' of dirt, light fixtures inside the cage, and so on. I have seen suitable cages built using troughs, but you'll need a bigger one than you described.

I'm basically picturing a hibernation box with lighting options for days their GU wants to bask. My boy occasionally pops up on warmer days then goes back down for weeks, or even months. Argentines tend to spend the better half of the year sleeping underground.