It's not too much of a problem in our house. Over a period of time there's some slight discoloration immediately over the shower and that's about it. These Victorian terraced houses of the kind I live in actually run quite efficiently at low temperatures. When Xylia was away for a long period of time a few years ago I kept the knob on 10 C all winter and the energy costs were very reasonable indeed. Our 19th century forebears probably would have done the same, as they typically wore a lot more layers - woollen underwear, waistcoats, corsets, crinolines and farthingales - and for heat they'd have a couple of bits of coal smouldering in the grate. It's only latterly that we've come to expect to be able to wear T shirts throughout the winter and that the situation has become so costly. Out of interest, here's the Met Office graph of average January temperatures
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So as you can see, it wasn't hugely different around the time my house was built. In 2020 the temperature climbed to climate emergency levels of 5.5 C but overall, the year to year variability is a lot greater than the long term trend. People in the past knew a thing or two about keeping themselves comfortable.