They don't 'require' much more space. A neonate will do fine in a 20gallon long until about 3-4ft. They don't stress out from too much space like balls do though, but they won't move around all that much as an adult.
An adult will fit happily in a 4x2 reptile cage.
When they're young they tend to be more climbers and baskers than hiders. My RTB doesn't use his hides very often, but will burrow and climb on his branches. He's the only one I have equipped with a heat lamp to provide proper temperatures on his branching platforms.