I live in sc the upper part,where I dont have heat due to the moderate weather.can most of these pet birds handle and indoor temp that might average 40-45%at night.or even down to a rare32%.
I would have them in a room of say 10×10′.
Birds do not tolerate fluctuating temperatures very well. Wild birds are used to it, although even they can be affected by extreme changes. Generally once you get to 50 degrees Fahrenheit or below, this is too cold for caged birds. You will need some type of heat source if you want to keep pet birds healthy and comfortable. Unfortunately, space heaters are generally not safe to leave on unattended so I am not sure what your options are.