I would choose floor space over height. They don't need to climb, and will be sleeping most of the time anyway. Mine adults are kept in tubs that are probably 36" X 24" X 6". But you don't want that much floor space for a baby, a 10 gallon tank should do, or a 6-12 qt tub.

They will climb if given the option, but I think it's more of a plan to escape, and most fall. Lol. I guess they are missing their hanging on muscles.