Actually, there's another option. One they've already dipped their toes in thanks to lost footage: animation.
Why not animate some Big Finnish stories, or animate some new stories in that vein and call in the original doctors to voice them? If they can do it for audio plays, there's no reason they can't do it for an animated show. The hard part would be finding the right studio and animation style so you don't get Doctor Who Go.
Indeed, that could be a good option, done right.
Done poorly, we could end up with (yet another) inferior product.