Just to make one more thing clear: I am not disappointed with the Christmas Special because Audrey + Siegfried did not get together in that special.
I have read that as a main reason why some fans have not enjoyed the Christmas Special many times now. And I understand why some people would think that. But it is not that at all. Please do not dimiss the criticism and disappointment some fans share purely as "shipping drama".
I've watched this show since the beginning, I've been with this slow burn ship for 6 years now. I am patient, I trust the process, I know they will get there in the end. And with each series we get one step closer of removing all the obstacles that stop them from finally admitting that there is something between them that goes way beyond a work relationship and friendship.
The issue I have with it, is the way the Dorothy storyline was introduced and handled. And that does not mean I am mad that my ship did not sail in the Christmas Special. It means I am disappointed that they chose to bring Dorothy back in the Christmas Special after not having mentioned her for 5 series and after she's been absent in canon for 8 years. I also think that the way they made her and Siegfried immediately fall for one another again was done in a rushed way that could have been extended over several episodes. Instead we are returning to Siegfried's abandonment trauma and make him pick Dorothy because she is the easy, safe choice that saves him from being alone again. Regardless of what that means for the relationship between him and Audrey and Dorothy.