Hello & Welcome to BYC!
That is so exciting that your chicks are coming so soon! They should be fine in the garage with their heat lamp. You should place a thermometer in there to monitor the temperature, and as long as it is the right temp, you're good to go! Lots of people have their brooders in the garages or barns, so you should be fine. You can set up the brooder ahead of time and turn on the heat lamp to check and make sure everything is the way it should be and is warm enough. We have our brooder in our basement with no heat, and it is much colder down there than the rest of the house and chicks have been doing fine down their for over thirty years. Good luck!

