Bayern Munich still remains the favourite and has mostly the chances of winning, over the weekend they had a good performance and win in their domestic league, which could definitely means their morale and mentality at the moment is right and high enough, ready to take on any team, especially at the UCL where they are very much aware of the level of competition they would be facing.
Galatasaray may want to fight for a draw with Bayern Munich but I doubt if Bayern would give a chance to sharing points with Galatasaray Even if Galatasaray is playing from home because this game will give a determinant to their qualifications for the next rounds of the UCL, if they get a win against Galatasaray they are getting a smooth sail to the next stage but otherwise they will have to work hard again.
It's just that Bayern Munich player composition is incomplete. Several important players had to be injured so for Galatasaray this was an opportunity they should not waste. On paper I know Bayern Munich are the favorites, but because of this UCL makes the mentality of Galatasaray players difficult to predict like against Man United.
Tuchel task will not be easy, because he knows very well how difficult it is to close down the movements of Galatasaray players. If I'm not mistaken, during the Champions League the two met only twice (Bayern Munich won once and drew once). That means it is still difficult to use as a benchmark when facing this Turkish club.