buttons do well outside without heat down to about 50* I keep my flat panel cozy coop heater on low as needed, and covered the outside of that aviary during the odd weekend that dropped to freezing temps. mine are in my pergola style sub-aviary with my finches and budgies.
https://www.backyardchickens.com/posts/21837639
this thread has some cool button housing ideas
my buttons are currently outside in my pergola style sub-aviary but for indoor housing, you can use aquarium, bird or small animal cage, or custom-built cage housing with fake plants, and hides...