I really feel for you. I feel the cold, I hate being cold, I am originally from a hot country and resent every single penny that I spend on heating. I spend £140 on a four bed detached house in the north.
I have bought teddy bear bedding for the children and I so we don’t have to get into cold beds. I work from home and wear a ‘wearable blanket’. I heat a hot water bottle or similar so my hands and wrists don’t touch the cold desk! And I sit on a fleece blanket so no cold air hits my back.
I think your husband is being selfish and a bit of a d**k. Seriously, no-one hates a cold house more than me, but there are better things to spend money on than giving it to utility companies. Like holidays abroad in the sunshine! You should get to decide, as a team, what the money gets spent on. Even if you can afford £600 a month, it’s still insane to give it to utility companies (in my opinion).
I was recently told that if I updated my radiators I would get more heating bang for my buck. You definitely want thermostats on the upstairs radiators so you can turn them off.
I have used the plastic over the windows and it definitely works if you have draughty windows.
If you have rubbish windows, then all day, the warm air is being sucked out, and replaced with cold air. You might as well stand by an open window throwing cash out…
I hope BG got it wrong and that you have a nice refund coming your way!