is this your own house, or rented?
how thick is the loft insulation?
does it have cavity walls, and are they insulated?
how old is your boiler, and is it a combi or does it have a cylinder?
what size is the radiator in your bedroom, and what size is the bedroom?
(these are all clues that will give pointers about other things)
but
Heat transfer from a hot object to a cold one is directly proportional to
1) temperature difference
2) time
and some other things
so keeping the inside of your house 10 degrees warmer than the outside for 24 hours, will lose twice as much heat as keeping it 10 degrees warmer for 12 hours. Keeping it 20 degrees warmer than the outside wil lose twice as much heat as keeping it 10 degrees warmer.
There are additional comfort quibbles about how long it takes to get warm from cold, and how long it takes to get cold from warm, and how many hours a day you are at home, but they do not affect the laws of heat loss.