I keep 14 cresties in breeding pairs and trios, all in exo terras' (45x60).
Exo's are brilliant for humidity if sprayed regularly - I spray twice a day, and I also live plant. I have 3 45x60 exo's ready in case of seperation (and to seperate my males to give the girls a break) and as far as I'm concerned this is a must for any good keeper; better to be safe than sorry.
I agree with the above posts, 3ft does limit you but as it's a wooden viv it wouldn't be suitable for the high humidity requirements or live planting. Maybe a leo?