Should I let my quail out of the house yet?

[QuailHead]

I got some 3 week old female quail last Wednesday and I've weaned them off the heat light to room temperature and I'm not sure if I should let them out into my outdoor fenced in enclosure yet. The lows here are 40 tomorrow .

 

[Binki]

They still look a bit ruffly to me, I would think the cold and possible wind wouldn't be good for them, maybe in a week or two when they feather out more - quail chicks are really susceptible to drafts I hear :O