@Sarah977
The cats poke holes in the plastic film? Really? I had never even thought of that!
Here you can buy some thermal plastic film that is specifically designed for this purpose and therefore doesn't require any sticky tape. I am thinking of giving that a go, only I've heard it's impossible to remove and what if it makes the room too hot in the summer?
I have tried the strips that stick onto the edges of door and window frames to isolate gaps, but they didn't work. They just seemed to disintegrate in no time.
The bedrooms, bar one (with shutters because of the shape of the windows) have curtains, but I think I need to buy some thermal ones to go with it. I encourage guests to close their curtains at night and tuck them behind the radiators so that more heat comes into he room and less goes out of the windows, but I have no control over whether they do it or not. I have heavy curtains in the living room which I always make sure to close in the winter when it gets dark.
I also have draught excluders at the exterior doors and also for the bedrooms. I tried stuffing the chimney breasts with bubble wrap or similar, but it just falls out.
I feel like there is a lot more I could be doing. I think the heating is sufficient (the costs are very high compared to the electricity bill, which is very reasonable for this size of house).
My house is around 200 years old!