Like one of Mrs Patmore’s proverbial soufflés, Downton Abbey in film format is light, fluffy and permanently – perilously – on the verge of total collapse. It is not, as some have suggested, merely akin to an overlong episode of the television series that took the world by storm between 2010 and 2015. No. What has been created here is a whole series, truncated to singular feature length; a full box set lacking only advert breaks and next time teasers. One can almost hear the twee inflections in John Lunn’s divine score that ought to herald commercials, and will one day soon with ease. Despite sleeker visuals and an afternoon spent filming long shots in a helicopter, this budgetary upgraded Downton won’t win new fans for the franchise but should prove to be the icing on the hard core’s cake.