Rectangular single-family house on a narrow plot

I share your concern that the large room could become "long and narrow" – but not because of the layout, rather because of the placement of the drawn-in furniture. Structural and view-breaking elements are difficult to integrate in this way. A lot of table and a lot of sofa space for 2 people. With the right choice of furniture, plants, and possibly a piece of furniture protruding into the room or a chaise longue positioned crosswise, the room can be visually harmonized. A larger window front would also visually open up the room.