In the quarterfinal, it is almost certain that they will meet Spain/Italy and if they win = their opponent in the semifinal will be Netherlands or Portugal.
Are you pretty sure that Italy and Spain will pass their group and that Croatia will not be a problem? This is the same team in which players like Modric, Guardiol, Kovacic play and which has won a medal at the world championships twice in a row.
To win the Group B, Croatia must at least be able to win 2 times with 1 draw, they will win against Albania but I doubt they can get 3 points from Spain or Italy.
That is why I think Spain or Italy have a bigger chance to become the winner of Group B and one of them will face Germany in the quarterfinals after beating 3rd place from Group A/D/E/F.