Bayern Munich is not at their best feat but this doesn't mean that there is no room for an improvement over time. If they didn't improve at some point in the season and Dortmund did not relax, they wouldn't be topping the table now. There are still 3 months to conclude the season, anything can still happen and people would be surprised.
We should not be judging by the 6 goals scored by Dortmund against their opponent in their last match, it happens like that and doesn't stop the fact that Bayern won their last match too.
Until the end of the championship there are 3 rounds and not three months. ) In fact, Bayern still have a difficult match with Leipzig, and Dortmund with Borussia Mönchengladbach, the rest of the rivals are not so difficult. That Dortmund are in better shape may mean nothing, if Bayern win their remaining matches 1-0 they will become champions. But one point advantage is really very little and Dortmund still have chances, they need to win and just wait for Bayern to lose points.