Following on from your post and Honey Badger’s, an electric blanket can work well and some come with a timer so it takes the chill off before you get warm and fall asleep.
I think electric heaters come with an auto off breaker if it falls over.
Something I did last year and when I was in university students accommodation (years ago) was to tape good quality clear kitchen plastic wrap over the window frames! I think they sell special purpose film in hardware shops, but cling film did help reduce drafts!
A heavier set of curtains from a charity shop would help too.
Changing your clothing can really help.
I know Princess Diana swore by her Damart type underwear, but it makes me feel way too hot, I always wear cotton.
My father in law wore ankle length pants in his draughty cottage, but it would have been better to deal with the draughts.
In winter I always wear socks (after 2 knee replacements I struggle to put tights on) and if it’s really cold, my “metal knees” seem to really feel the cold. So I wear men’s HJ cotton “golf” socks from ebay, these have a fold over top, but I don’t fold them over, just pull them over my knees.
I also wear cotton corduroy trousers - Dash used to do some that fitted me well, but sadly they’ve gone out of business now. I dug a pair out of the wardrobe this morning as it’s been raining all day in the New Forest. (Three weeks ago I was sunning myself in Crete in temperatures around 30 degrees).
I would also recommend Peacock’s cotton ladies vests/camisoles, only £3-£4 each, lots of colours.
In my tiny ensuite I have a small over the door fan heater, which I put on a few minutes before my shower, makes a real difference.
Every year our council run a winter warmer campaign, it gives a grant to a charity to promote keeping warm etc for elderly/disabled.
If you have no or bad central heating and are on low income might be able to get a better system supplied.
They advise keeping temp minimum 18 Centigrade, keeping doors shut, wrapping up warm, blankets, draught excluders etc.
So might be worth contacting the council.
If you feel cold at night, I’d recommend wearing socks in bed. It makes a huge difference.
Also, make sure bed is nice and warm before you climb in. I prefer a hot water bottle to an electric blanket, as I can kick it out if I get too warm.
I am using one by BLACK + DECKER portable heater and it performs really well. It’s only for small to medium-sized rooms. But you can find them in all sizes.