[MovedGoalPosts]

In many respects how things are going to work best will be a balance between what you can afford and how your home is built. Think not only about energy and air temperature, think too about structure temperatures, condensation and other risks. Frequently I see problems where people raise the air temperature for short periods, without ventilation, the warm air supports greater humidity, yet the walls and other surfaces are cold and people then complain of black mould condensation when the warm humid air hits that cold surface.

It takes a lot of effort to heat a building from cold. If you are only heating for 2 or 3 hours, especially in poorly insulated homes, it's possible your home didn't even get to the desired temperature.

Equally it is unnecessary to have your house heated 24/7 to it's comfortable occupancy temperature. That is just wasteful.

So find a balance. My house has solid walls, difficult to insulate, so I don't want it to cool too much, both for condensation risks, but also that on the coolest days it takes too long to get to temperature. Thermostatic radiator valves control individual rooms so those that are less used can be kept a bit cooler. But the programmable room stat controls the heating system that is allowed to be on 24/7, to keep the house at around 19 deg when I get up and am rushing around to get to work, so don't need comfort temperatures, 14 deg during the day, 20/21 deg in the evening and around 15 deg overnight. Unless it is really cold the system doesn't have to come on much during the day or night