Ideation, yours sounds a similar set up to mine with the sleeping area inside the garage. First tip is don't make the sleeping box too big. If they can jump of there bed and walk around inside the garage, they will probally piss on the garage floor instead if going outside into the run, especially in winter. Also I wire the heat lamp through a thermostat too. Saves on electric and stops the dogs cooking. I wouldn't worry too much about insulation the sleeping boxes, as your gonna have a hole in the wall into the run open 24/7. It's a bit like insulation your walls but leaving the door open. Go