I am well educated in sleep science & assess sleep as part of mental health assessments. Good on you Vy (2017) re CCI www. I usually find people want to tell me lots about their poor sleep. After I have learned about their mental, physical health & lifestyle I offer advice to improve their sleep IF they want to know. Mixed results. Why? It is rare that people want to address their lifestyle, not least alcohol use. Most assume there is a pill available. I am not a prescriber so I don't have to enter that discussion. Why am I writing about this in Houzz? Bedroom design. Bedrooms are only for sleep, intimacy changing your clothes. Thus keep them plain, simple & DARK. Stop making them full of all the light you can get (small windows please for ventilation & easily darkened at night). Bedrooms are not for entertainment including all forms of media (Yes sleep apps are great) & family parties. Blue light in the 60 mins before sleep reduces melatonin by 50% speeding up dementia, cancer depression, anxiety, etc . Huge rooms are a waste of money since they only for 8 hours of sleep, at night, in the dark. The best news of all: increase anti-carcinogen, & reduce dementia onset activities, that only happen at NIGHT, in the DARK when you are ASLEEP for 8 hours. Sorry shift workers. Learn about this.

As you haven't supplied any measurements, it's a little hard to gauge the correct size of the lounge etc, however, I would definitely take the dining table out of the lounge. Like oklouise, I would set that up in the kitchen area. I would opt to place it hard against the laundry wall and pull it out into the kitchen when it is required. I would also opt to have a narrow table that could be lifted to become fullsize. How friendly a terms are you on with your landlord? I would be putting a good case forward to him/her to install a heat-pump high on the wall above where the dining table is in your pic. There looks to be an area outside the WC wall to place the outside unit and it would be very easy to duct through to install the inside unit. While at it, get the heater taken out. Hopefully, the landlord would be able to see that a heat-pump would be cost effective whilst freeing up the corner for you. Do a little research beforehand. I would put the TV, and other lounge cabinetry on the white wall that backs onto the kitchen and if possible, around the corner slightly, where the heater is. That would free up the remainder of brick wall that has no window on it, for you to arrange your seating. As already suggested, I would also set your guitars up near the base of the stairs. Thoroughfare from the entrance, to the stairs, to the outside and to the kitchen and bathroom needs to be an uninterrupted flow.

I’m set up in our sunny spare bedroom. Happy with my spot as I have views to the street and a desk to work from.

Just my opinion and I’m no expert : D If you wanted to hang onto the lounges for a little longer as they are very practical while you have a young child and dogs, I’d look at trying to find a cushion that might combine the colours perhaps? Like the pic attached? I’d also use some conditioner on the lounge and maybe put a bit more stuffing inside the lounge seat cushions yourself. I did this to a Parker lounge and after a clean and leather saddle conditioner it didn’t look too bad. Maybe a big square (so it won’t tip over) pot with a dark green plant like a peace Lilly, cast iron plant or a tall plant could make the green lounge fit in a bit better.