I am planning to add scatter cushions and think if I do a pair of larger ones for each end so they go over the arms to creat height at each end, and a couple of smaller ones, I want to bring some colour in too. I do like the idea of a larger side light at either end to, Switching the sofas is going to be my final fix if all else fails!!

Well, for lack of a better idea, since you find it a drafty little space. I'm assuming the draft comes in on the right? Most of the necessities in the area are located of the left side; i.e. vent, thermostat, light switch etc. What I would do I think is caulk up the drafty spots, maybe even add sized poster board wrapped in batting I covered in a gorgeous fuscia with diagonal grosgrain ribbons every which way covered with a heavy velvet to be attached to the area above & below the window. (Of course remove the drapes that are hanging in there). This for the purpose of using it as a pin-it board for notes. Attach a table height board covered in felt to carry across the full width of the little room. Leaving just enough space for a comfortable little antique desk chair. Paint the back wall a bright cobalt blue, paint the ceiling a silvery pearlescent white. Find a way to attach a clip-on task lamp. And stretch a heavy duty enough wire across the top of the opening and complete it with a heavy doubled velvet drape with a drooping valance. Place a swag with fringe & jewels on it to be closed when not in use. Voila intrigue is yours!

These chairs are easy to recover and the range of fabric available today gives you plenty of choice. I say go for it. If you don't feel up to it yourself get an upholsterer, but plenty of YouTube tutorials about.

An entire wall of built-in cabinets and hooks and cubbies for your crafting stuff (and perhaps filing-type stuff and printer for the office). Take a good look at what you have and think about how best to organize and store it and what could be displayed to be pretty and what should be hidden behind curtains or doors. A fold down ironing board on a wall or back of a door somewhere would be great. A nice desk and filing cabinet for the office side... or perhaps a great big table in the middle under the window, wide enough to function for both of you facing each other? A nice curtain rod would make a big difference too. Preferably just about floor to ceiling. I'd put a splash of colour on the walls and keep the curtains simple, but you could go vice-versa too. Something like this: [https://www.houzz.co.nz/photos/modern-bungalow-phvw-vp~4999540[(https://www.houzz.co.nz/photos/modern-bungalow-phvw-vp~4999540)