I just checked the 5 day forecast for Ogden, UT. Highs near 50 and lows around 30.
I have to say, although your town may be somewhat colder, I don't know, but it is only November 1st. Winter is coming and will be worse, no? The whole heating thing escapes me, personally, but I know others feel the need. I don't know what I'd do with a broody Silkie in the flock. Are they not about the broodiest thing ever? Brooding now seems out of place, to my mind, in our climate, but what do I know?
For certain, this can be said, 200 watts of light is much too bright. Poor chickens wouldn't get much rest. Sleep deprivation would be crueler to me and my mental well-being than bamboo shoots under my fingernails, I think.