It is never too hot but too cold in Ottawa for most of Chinese.
Our first house had the same layout like the one you described: master bedroom was above garage (facing south), kitchen and family room were at the back of the house (facing north). When we spent time duing the day in the kitchen or family room in winter, it was cold because there was no sunshine. When we slept in the master bedroom during the night, it was cold because it was above garage.
Our second house has kitchen, family room and master bedroom all at the back of the house, facing southwest. There is lots of sunshine during the daytime in winter. It is perfect. We haven't experienced summer in our second house but we don't worry about it too much.