I almost wonder if the Christmas special might be able to be bumped up in budget and length and turned into an annual theatrical release. Christmas Day is already one of the biggest movie-going days of the year, and making it a theatrical release with a bigger budget and more flexible run time might attract some name directors like Jackson.
Even assuming such a thing were to happen (and I agree with the above saying it won't ever happen) why would it mean increased budget and length? Day of the Doctor didn't get either. And wouldn't having a special longer cut of the episode shown in theatres and not on TV be a violation of the license fee?
Even if another DW episode got theatrical treatment, all it would be is the exact same episode that airs on TV shown on a theatre screen with maybe a behind the scenes special and those Strax theatre etiquette things. And since UK theatres are apparently not opened on Christmas, that rules out any Christmas specials getting the treatment. Though I suspect that if another episode did get a theatrical screening, it'll probably be the next episode to be considered an event, like Capaldi's first episode.