Hi there @Robjnack
If you look around you will find natural birds, maybe younger than your hoping maybe not don't give up, they are out there...
I have a large mixed flock from lots of differnt origins, they do fine together ( ranging in age from 5 years to 2 months, standard sized birds and...
Sorry I missed what kind of birds you had ( or if you have any yet ) but avoiding the big single Combs, look for breeds with button or rose combs, that will definitely help in your cold temperatures... Without the big combs you probably will only need to worry about their feet, and that can be...
I think the heating panels consume less power than lamps, also less risk of fire... My birds have been through -40 but it was under a week, with a heat lamp. Apparently the deep litter method can raise your coop by 10 to 15° in the Fahrenheit scale so that's something to think about too :)
Heats not really a necessity until it's about -23 then it's pretty helpful, as long as there are no drafts and good ventilation thing should be just fine, i've never had an insulated coop, I try to only heat when it's really cold and I use heated waters located in the run ( not in the coop...