Or use a layer of
Panda film on the walls/ceiling of your grow box to hide from infrared.
But yeah, insulation of the attic will def help with the temperature as well.
Boston gets about the same weather (temperature-wise) as Buffalo so if your attic gets as cold as mine I'd think you'd have to have an insulating layer on you grow box as well. My shit gets down to about 45-50 in the winter and 90+ in the summer.