All your suggestions for their safety are good since it sounds like you are in snow climate. I'm glad to see you are mindful of Silkie protection - Silkies act tough but they do require some special treatment and segregation from heavier large fowl breeds that can suddenly become bullies - it's a chicken thing to peck on smaller or gentler breeds. I am nervous about electricity/lamps in coops/pens as I have read a lot of horror stories of fires but that's just me being over-cautious. Use your good instinct for your Silkies' protection.
We don't get snow but for rain protection we have a popup canopy over our small coop with the legs buried in the ground to keep from para-sailing in the wind. We have a 4x4 indoor kennel w/gate that we use as a quarantine/hospital pen and we put two Kidz Homz plastic storage boxes lined with straw (look a little like small kitty litter boxes) so the Silkies have a place to lay their eggs in-house - we clean the straw every day because the Silkies will sleep in the boxes too. If you decide to keep them indoors be prepared to change the floor liner daily. If you use diapers you can let them wander around the house too - our Silkies got very tame being indoors during quarantine - might as well enjoy them as pets if they're indoors. Be prepared to sometimes find an egg in the diaper! LOL! A hanging nipple waterer will save floor space and deter a soaked flooring. I agree about the small coops not being able to house the amount of birds they claim. Always figure half the number of birds suggested by the mfr.
Good luck with your Silkie girls!
