Cunning plan....NOT!

I was in someone's house once that had a log burner and they left the doors open to let the heat spread through the house and this did work

The problem with this spec is there is a passageway between the dining room and the living room.The warm air would need to go through the dining room door, along the passage and into the living room door. The warm air would rather travel up the stairs than go along the passage and do a right angled turn!

True enough the cottage I was refering to had an external door leading into the kitchen where the fire was, the internal Door on the opposite wall opened into the hallway where all the other rooms came off it

This doesn't help you either but..................... the little cottage I bought in West Wales had a central chimney between the bedroom and living room. The previous owner had put a double fronted woodburner there, with glass doors that could be opened from either room. The initial effect was great BUT because the stove wasn't built into the opening but just sat on the hearth, there were big gaps at the sides of the stove through which you could see into the next room! The stove had to work twice as hard because it was heating two rooms, not one. - and the cold air whistled through when the front door was opened!!
I had wooden shutters made to close off the bedroom side but, soon after decided on adding an upstairs floor with living area. The chimney breast was blocked up one side and the staircase built against it.

When we first got the house OH wanted a Victorian type tiled fireplace in the living room. We then fitted the woodburner in the back room.If we hadn't paid so much for the Victorian fire OH then said we should have had an inset woodburner between the rooms.