But you can also look at a smaller fireplace. We had a modern one installed a couple years ago, < 70 cm wide and builds only 40 cm from the wall (chimney) - and it still delivers 5kW - more than enough for your nice little house. ok

Here is the result using a smaller fireplace:



And here is the bedroom upstairs:



I received a suggestion to try to invert the stairs because maybe the space was smaller when someone goes up, considering the slope of the roof and so the result:

First floor



Second floor



Thank you all for the suggestions!