The answer is heating zoning, and the solution is Evohome.
Is this always the case? Would the size and type of property and occupants requirements make this unsuitable in certain situations?
I looked into this a few years back, but decided it wouldn't suit my needs. I came to this conclusion after playing with the existing TRVs to reduce the temp of unused rooms and discovered that overnight the whole house became colder. I guess this was because theres no insulation between the rooms (stud walls) so the rooms slowly leek and leach heat to reach a near similar temp throughout the house.
I can see the advantage of heating zoning if you live in a large house and/or happy to leave the heating running over night.