My concern would be how predator proof is the run. You can train them later if you feel the need.
It sounds like you have been acclimating them. At five weeks they can easily handle a low of 65 F. I've had chicks 5-1/2 weeks old go through nights in the mid 20's F. Even if you are talking...
Many people suggest one week to get them used to the idea that the coop is a safe place to sleep. Chickens tend to put themselves to bed when it gets dark in the same spot. Most of us want that to be the coop so we can lock them in there away from potential predators. For many, one week is...
That's because there is no "one" way or "best" way to do this. That applies to almost everything to do with chickens. You have so many options it can get really confusing.
They are six weeks old. I don't know what temperature you keep that garage but they do not need any supplemental heat...