Great post!
I am also in a very cold region, and although I wore shorts and a t-shirt today, I know that frigid temperatures could be right around the corner.
I live in a house built in the 1880s that is predisposed to drafts and general chilliness. My bird room is the small sun room, which someone at some point converted from an open front porch. It is not the coldest room in the house, but it isn't warm either. In winter, I usually cover the windows in plastic, some years both inside and outside. I am getting ready to caulk the windows on both the inside and outside as well.
I do not cover my birds at night, but I close the thick window curtains, which are tight up against the windowpanes. If the temperature outside is really low, like below -10 F, I usually leave the curtains closed during the day as well.
I use a wall unit electrical heater for about six months out of the year. It runs full time for about the three coldest months and keeps the temperature to at around the mid-sixties:
Wall Mounted Electric Heating | Best Electric Heaters Energy Efficient | Envi High-Efficiency Whole Room Electric Panel Heater
I use a cool mist humidifier that I refill every morning. I try to keep the humidity up to at least 40% using that device plus about twenty small- to medium-sized bird-safe houseplants. It is still a struggle as the air here gets incredibly dry.
Has anyone used those snuggle heaters made for birds? I am tempted:
https://www.amazon.com/Manufacturing-Snuggle-Warmer-Medium-Large/dp/B00CLA19BQ
Or the heated perches? I am tempted by those as well:
Bird Perches: Heated bird perch: Thermo Perch
Any other tips are greatly appreciated!