Bundesliga matches will resume in mid-January next year and I think Dortmund can definitely get a change in their playing pattern in the upcoming matches. Because now all the teams in the Bundesliga are starting to have more time to develop the best strategy again before the next match starts again this season. Moreover, the winter transfer market will also open in early January so all teams must make sufficient preparations to be able to buy better players for the remainder of this season.
Bundesliga teams have enough time recovery performance because matches will resume on the middle on january next year and some teams can get recovery with their player with injury. Dortmund is one of Bundesliga teams with inconsistent performance however their good result achievement success qualify on Champion League but their performance not quit well in domestic league.
Seems Dortmund will not active on January transfer window and keep focus with current their squad although have to play in champion league and get consistent performance in domestic league.
If you want to know if they will be active during the january transfer window then you need to follow them on their official social media handle. Talking about Dortmund performance, indeed i would say they have been impressive this season. I am not against the way they played in the bundesliga. But in the champions league they performed well because they played against a very competitive teams over there. Still they were able to manage and qualify tor the next round. That alone is enough to impress their fans.