Chelsea has now three opportunities to play against teams that are not in top shape in the Premier League. Perhaps this win against Dortmund now gives them a push and they can improve. If they started a winning streak now of three consecutive games, they would afterwards host the game against Liverpool and that could be their final chance to keep a realistic probability for the qualification for the international ranks in the table. I doubt that they can still make it 1-4, but if they win a lot of games the Europa League could still be achievable.
Usually, Chelsea will fight and struggle when meet a strong team and be careless when meet a weak team. By winning on the champions league last night, It does not mean Chelsea will able to win the next match versus Leicester and Everton. As I know, Chelsea is seem not focus on premier league, maybe they searching another way to keep it strong by focus only on champions league.