I'm not laughing. But I am smiling
People tend to put insulation at the top of the list, which I agree with, but I think joint top are the simple measures such as a jumper etc, etc.
I have thermal long johns and tops, thick socks etc which I wear throughout winter. The house is usually around 16-17c in winter at peak. When it r occasionally reaches 18-20c we start to get hot under the collar and unconformable, even without the thermal layers. Most people naturally acclimatise to their environment; be it levels of heat, hunger, etc. Heat a house well into the 20s, and over the years you'll feel the cold a lot more as your body resets to the new "normal". I totally accept that different people have different tolerances, but at the same time I think the above holds true.
I personally can't understand why how we use energy is often not discussed, or at least left to the margins. So many people have a shower a day (some more!), wash clothes after one or two uses, heat houses to the point they can sit in shorts and t shirts, etc etc. If we hadn't evolved into this era of cleanliness, I think a lot of what is now considered normal would be considered anal OCD type behaviour. We scramble around looking for new innovative ways to make everything greener - which is a great thing - but for me the elephant in the room is our usage.
I feel I must say something on topic now to counter my off topic rant! To the OP, I would be inclined to stick with what you've got for the time being. I think we're in a period of flux and it's hard to know what the future will hold for different energy prices, changing installation prices and grants, new green legislation, and new innovation in heating systems which perhaps haven't surfaced yet.