Oh dear, you have got a sticky situation here, haven't you? You don't want to block the window or the radiator, and you probably don't want to cover over the chimney breast either which really limits your layout options, but I would have thought that the option above would make your room 'feel' quite an uncomfortable place to be. it seems to me that the best solution would be to move the bed arrangement to the left hand wall, so that you don't lose any of the aspect from that lovely huge window. I would put in a partition wall facing the doorway to the room and insert the sliding robes behind it, so that you are not looking at the end of a cupboard as you walk into the room, but at a wall with a lovely mirror or piece of artwork on it. This would also have the effect of leaving your fireplace on show so you can style it and give you a good amount of space in front of the robes for dressing and posing in the mirrors. Diagram attached. You will not get 2.2m of wardrobe this way, but it does avoid compromising the room layout. Hope this helps and sorry the diagram's a bit dark :)