A rising politician of the 1920s who only just moved into London?
Whose new home is a former workhouse?
And who's running this huge place with the help of a single housemaid?
And the housemaid doesn't even live in?
No way. Politicians have always had to have a London pied-a-terre; the job demands it, no-one with social ambitions would have moved into a former workhouse (so infra dig- and besides it would have needed to be completely remodelled) and those big houses required huge staffs- not only because of the practicalities but because of social prestige.
It was a lavish production. Maybe they should have spent a little more and hired a researcher to watch Downton Abbey so obvious howlers could be avoided...