It's clear that a huge advantage has been lost, but it's not over yet. The teams have three more games to play. Dortmund still has a chance, considering that Bayern will play with Leipzig and Dortmund will only play with mid-tier teams. What they have to do to use it is to win all 3 games and wait for Bayern to lose points. The sensational result of 6-0 today also shows that Dortmund is still in this race psychologically. Last week's Bochum match draw was very hurtful for them, but there is still hope.
The big win in this competition made them motivated because of course it was a very big win.
Although that is indeed the case when talking about Bayern in the rest of the competition they will still be fighting a team that can be said to be strong but of course this is also not a reason for them to give up.
The current condition is that they cannot lose with less and less games and conditions that are really hot for the Bundesliga.