Excessive heating of the winter garden can be reduced by using not only a roof awning, but also a vertical, otherwise called reflex. In addition to the plating made of material, you can use a small "mesh" (screen), which after leaving it protects against penetration of sunlight and intrusion of insects into the room.
Automation
Solar automation will automatically develop the awning when too much sunlight falls into the winter garden. It will prevent excessive heating of the interior of the winter garden.