My prediction is actually 2-0. In the champions league Pep doesn't seem to want to score many goals away from home, and he wouldn't want to risk needless injuries. If they scored 2 goals I think they'll take it a bit easy, and the game might finish 2-0. If you have watched their game against Arsenal, they were even somewhat satisfied with 1-0 even though Arsenal were playing with 10 men.
2-0 away from home, after all, is enough for them to progress. We're not going to beat them by 3 goals at Bayern.