I have always been a belt and braces kind of person and had both gas and electricity until I moved here. When you look for flats for older people they seem to think we are incapable of looking after ourselves despite reaching a reasonable age without their intervention. I tried everywhere to find a suitable flat with gas , but nothing doing , and so have had to have electricity. Personally if you have the chance to keep the gas I would be inclined to keep that, but do you have anywhere near by if you are old enough to have a word with someone like Age Concern, as they often know the good things that work in your area, or would be able to put you on to the right people to help. I would definitely look at good curtains with linings which can provide another layer not actually touching the windows which will help to keep the heat in too. I lived abroad quite a bit , and I do use my curtains, to keep things cool in the summer and warm in the winter. At this time of year I make sure that I am closing curtains as soon as it gets chilly. In a house I used to shut the upstairs curtains as soon as the sun went down and on very cold days in the winter I never opened the curtains at all upstairs. It all helps a bit. Hope you find something that suits you