A one-off series/miniseries could work pretty well as (part of?) a break year. Maybe even put it in the hands of someone other than Moffat as a 'test run' for one of the potential showrunners.
That's an idea with potential.
Imagine a "Worlds of Doctor Who
" umbrella title for occasional one-off films. You could have Madame Vastra one month. The River Song/Jack Harkness thing that Alex Kingston and John Barrowman both want to do another month. Maybe a Rani and Clyde movie, to catch up on them since SJA
It would be a hard sell to the BBC bosses, though. Money would be hard to come by, probably harder than it was for RTD's specials year (and that, at least, had the advantage of being actual Doctor Who
). Foreign broadcast partners might not be interested in picking up these specials.
It is an idea with potential, though. But it has, I think, a steeper hill to climb than a series devoted solely to Madame Vastra would.