I have a mixed bag flock here, polish rooster, and a bunch of larger ladies, and my 4 silkie hens. There is some squabbling and like in any flock there are those that are more dominant. But I also have a mixed bag of ages so the youngsters get harassed mostly.
My whole flock are not overly happy with the heat and humidity- and can handle the cooler weather better.
Sub-zero temps though are hard on them - anything under -10C (14F) is very stressful for all my chooks esp the silkies. I have a sweeter heater for them to hang out under during the day, at night my Hen House warms to about the freezing point (32F) with all the chooks in there.
When I gets below -20C all my chooks are unhappy, then I make sure they have warming stations and ensure the Hen House is warmed to the freezing point (32F) for them at night.
Otherwise the silkies are just as hardy and happy as the rest of the flock.
One thing I should point out is that they need their head feathers trimmed so they can see, I keep my silkies and my polish Roo’s head feathers trimmed short so they can see anyone who wants to pick on them, and so they can hop on things, run around and for predators outside.
Silkies are little clowns 
