I have a varible temp timer
I have it set to maintain 14 all the time in winter - rarely comes on and 19 for 2 hour in the morning through winter for before we get up.
Right now heatings off
8 rads - 3bed house
We used 500 litres a year in all the oil fired houses we have had
We used the stoves and eco fan +open coal fire in office to heat the house when we are in though.
Could have paid a fortune to get gas installed last year but just stayed oil as its not stupid expensive amd lets me monitor costs as oppose to getting stung + easy to repair my self