Real Madrid seems to have an "easy" path to the title. To be fair, after a certain point you have to face a big team, but here they have a chance to beat Atletico Madrid, which they should be able to do, then face whoever wins PSV vs Arsenal, doesn't seem like a big deal.
Those are the two stages that will take them to semi finals, and at semi finals they will face probably Liverpool, or maybe PSG, basically they are going to have their hardest game there, but shouldn't be impossible in that case too, still looks like they would be favorites on paper. This is why I do not see how things could change for the long term, we could always end up with different results, it just doesn't feel as if it would be too bad for them.
I would not call it a easy way for Real Madrid. Though historically they have the highest number of titles but they are struggling this season at home league. They have even lost to Atletico Madrid in home ground. La Liga teams had been dominant in most of Champions League but considering their three way struggle and below average performance, this time PSG or Liverpool could be a better candidate. It's sad to see those two again playing each other in round of 16. Bayern Munich would be another contender and they have got an easier opponent who they are used to winning.
No team will have an easy journey in the round of 16, for that they must fight extra hard to be able to advance to the quarter-finals. We have seen how each team journey in the League Phase and the play-off round, all contestants face different challenges this season, even we may never have imagined a team of Manchester City class being eliminated so quickly. Real Madrid, Bayern Munich, Liverpool do deserve to be more favored, besides being more experienced they also have a more ideal squad depth. However, PSG, Barcelona, Atletico, Inter Milan and other contestants also have the potential to make a surprise and cannot be underestimated. We need to wait to see how each contestant is faring as the round of 16 resumes, their chances could certainly change if a number of key players are injured.