I personally don't think there is a "too big" for an adult tegu. I have an 8 ft by 8 ft outdoor enclosure, and I'm hoping to eventually get the 20 x 30 ft one rehabbed so it's safe to use as well.
Theresa Baker
No Legs and More
Florida, USA
"Stop being a wimpy monkey,; bare some teeth, steal some food and fling poo with the alphas. "
I assure you....you probably could never give an adult tegu too much space lol!!
Try a Boamaster...its what I house one of mine in 8x3x3. Great price for a nice cage
Mike
"They are biting out of excessive fear, not because they are mean. Mean is a human emotion and serves no purpose in the animal kingdom" - Kevin McCurley-The Complete Ball Python