Ah ok makes sense. I'm planning to do a pretty thorough build in a 12" x 12" x 18" and spend a great deal of time establishing the microclimate before I get the frogs themselves. I looked at John Clare's step by step and that gave me some ideas as to what I'm wanting to do. ie 4 to 6 months.
While I don't have as much experience with amphibians I do keep cresteds and while hardy they do have sensitivity to temps and humidity, so I feel like if that's the basis with thumbnail's being intermediate I'd be all right. Are you in the process of getting your vivarium going?