Hi Piet, I had to google where Okotoks is, for sure I thought it had to be way over on the East but you are just over the Rockies. I was getting Okotoks mixed up with Ozark's which are definitely more eastern but in Missouri, USA! good grief is my geography a little lacking in style.
We have our chickens in a barn which is insulated but I think I need to work on the ventilation, sometimes there is frost on the inside of the windows. If I get the ventilation sorted better then I won't need to worry so much about single combs getting frostbite. The first year we had a -30 and that was quite shocking for me but we haven't had that since. If it is -13 outside the barn it is -7 inside and that's when my thermocubes switch heat lamps on but so far we haven't been cold enough for that. Coming this week apparently.
I hope you find a rooster in that dozen to help with your breeding for smaller combs. I totally like the look of those chickens. I wonder if I am correct in thinking that the Barnevelder hails from Holland? - where you grew up? maybe I have it mixed up with another bird. I borrowed someones book on chicken raising and have given it back, think that is where I read about that. Odd snippets of information but maybe I'm wrong.