>cold in winter >in my region terribly humid
You need to actually reduce draft a bit (often old houses like mine tend to accumulate flaws that the elderly living there before didn't fix anymore.) and use a heating sources that matches.
Having a fireplace is fine. It could overheat the house whilst also keeping air dryer and it's essentially renewable (compared to the alternatives and houses made of more plastic insulation than anything else) if you don't mind air quality dip in winter.
That said i can see how that's no longer an option in places that have drastically increased their population
Fireplace is extremely inefficient, and really bad for both your (exhaust fumes get into the room anyway), and your neighbors (the smoke doesn't just dissappear) health, though.
I love the heat and smell of a good fire as much as the next guy, I'm just not sure it's worth the risk of cancer and respiratory diseases.
If efficiency is important, like if you are using wood for primary heat, you should at a minimum be using a sealed box stove which should be pretty efficient and have little to no smoke escaping.
Alternatly you could just use an outdoor stove that merely heat exchanges to the inside.