The fan, headlights and stereo are miniscule, less than 1%. The heat and A/C are different as they can cut range a good 10%.
I would also add that the A/C uses very little power, less than 1%. But then again it rarely gets much above 90 deg F here (32C). The heater uses a lot of power - try to use the seat heaters instead which consume comparatively little power and therefore more efficient at keeping you warm. Wipers are low but on a hot humid rainy day you have to watch out because rain reduces your range by up to 10% and you probably have to run the heat, A/C, and wipers all at once to keep the windshield clear. Probably lights, too. I see you're from Norway. High air density (when cold) also reduces range if you are going more than about 50 mph (80 kph). Cold batteries are a little less efficient. Keep it plugged in all the time you are not using it.
The Model S is a different car than the Roadster, but I created a chart that shows how HVAC affects Roadster range a couple of years ago. It's HERE.
The biggest factor is however how you drive. For me I find range increases when it wet or icy even if using heating & AC. This is simply because I drive more slowly and accelerate more gently which saves far more power than the lights / AC / Heater uses.
Interesting. My experience using the A/C is very different than yours. I can hardly measure any difference in range when it's on vs off. But the heater is a big consumer of power. I think the newer versions might have a more efficient A/C system.