Since Mbappe is not in form this season, PSG are finding it difficult to win their matches. I believe that PSG will get to the quarter-final of the uefa champions league because I see PSG beating Real Sociedad in the round of 16.
There's no such thing for a club to back down from the necessary actions. A good stage to see PSG shoots for higher rankings. PSG coach, Luis Enrique is in Parc des Princes and have been in La Liga before, trust me when I say, he can manage these competitive clubs because he's acquainted with Spanish club styles and he can perceived when he faces one top or mediocre team. PSG will definitely win Real Sociedad in the round of 16, that's not a game to contemplate about because this is the phase where the best team wins.
In the first leg of the round of 16, PSG has the potential to win the match because for the first leg PSG will be the host. And clearly this will make PSG much more confident in being able to beat Real Sociedad. But still, Real Sociedad is not a weak team, so it is possible that Real Sociedad will aim for a draw in the first leg and will destroy PSG in the second leg.
But you are right about Luis Enrique that this coach is the coach who best understands the style of play that Spanish clubs have. Because he has experience as a coach at Barcelona for quite a long time and then as coach of the Spanish national team for quite a long time. So he might actually be able to make PSG beat Real Sociedad quite easily.