I turned my thermostat down to 19c a few months ago.
I mainly do the washing up in cold water, only me and the cat here now so there’s never enough to put in the dishwasher. Combi boiler gets a 15min blast for a shower and that’s about it at the moment.
My lowest gas usage was .5 meter units last week as I had a shower at my sons and used his electric 🙂
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!