Well, I'm new to this too, and still learning like you, so hopefully you'll get more responses. We got our 6 chicks 3 weeks ago and I was worried about the same thing you are, since they are also in the garage. We've been fortunate; there was a heat wave in the weeks before we picked them up, but the temperature dropped and has stayed reasonable so far. Our coop is almost done and we just need to figure out the run.
So you could keep them all in the temporary shelter (did you check out the chicken tractors?) until the coop is ready? That seems like it should work, as long as it's predator-proof. I'd probably still start them in the garage and just watch there behavior, as LindaN described.
So you could keep them all in the temporary shelter (did you check out the chicken tractors?) until the coop is ready? That seems like it should work, as long as it's predator-proof. I'd probably still start them in the garage and just watch there behavior, as LindaN described.