And yes the carpet is going

Is the window floor ro ceiling? New seating or existing and how many to seat?

Window isn't floor to ceiling. All the furniture and carpet will be gone. We've got a 3 seater sofa and an occasional armchair for guests 😀

The most obvious place for the sofa is where they have it. What size is your sofa? Which way would you like to face as in is there a view outside the french doors? I quite like how their tv is wall mounted. If it was on a bracket it could be pulled forward for watching. What about an L shaped sofa along the same wall as the previous owners with the ottoman end along the left hand wall? You could put the sofa at 90deg to the doors but there are access issues and the woodburner might not be as visible. Its an attractive woodburner I would want to see it. Sorry only read your second comment now. I would set up my 3 seater sofa with the armchair at the end as though it was L shaped. I wasn't going to mention the carpet...

Would a tv fit in that corner under the window then? Sofa obviously on the long wall but nearer the entrance door with the chair towards the french doors and angled toawrds the sofa

If not then tv where they have it but centred and again sofa same wall and pushed towards entrance door

i would try them out before buying anything or fixing to the wall, you can always balance it on a cardboard box

If you go for the tv on the wall they have it consider painting the wall a darker colour to lose the tv

I would suggest having it the way they have it and sitting with it for a while. Don't do anything permanent until you've lived in the space and know how you move around it. Once you have done that then you can start making adjustments. I do, however, think that the way they have the sofa is probably the best bet. It just makes the most sense but I would move the sofa down the wall so it is not completely against it and the TV should be on a bracket so it can be adjusted when needed for the other person.

Thanks so much for the comments! You are all right that we should wait and get used to the space. Also really like the tip on using a dark wall to hide the TV. We may adopt something like this

I think a dark wall or panelling behind the tv is a genius idea. There are great ideas on Houzz for implementing it. If you fancy the panelling I have just received some oak and black slatted panels from AMC furniture and they were amazing as well as a really good price. Their price was much better than B&Q or any of the specialist companies like the wood veneer hub.