3-piece sofa fcan you draw a floor plan with measurements and indicate stairs, etc.?
If room a 3-seat sofa facing fireplace, flank chairs on either side. I like a hassock to use as a coffee table/footstool/seating. Add 2 comfortable small benches under windows on each side of fireplace. A round table with extension leaves. Lighten up all furnishings and introduce some warmth with textiles.

Oh I wish we could do your suggestion but sadly it's a weird setup.  The stairs come too far into the room and so a sofa turned facing the fireplace would be too close to the TV.  It is a frustrating aspect of the house that we didn't seem to notice until we moved in. Very disappointing.