I don't think Chelsea will let up the tension of the game just because PSG is a strong team right now, and I believe the London team has the speed to trouble the PSG defense. Chelsea just need to focus on dealing with the pressure from PSG's front line, and if they can play at their best, there's hope for Chelsea. Good defense will provide opportunities for counterattacks, although this can be difficult at times.
Everyone may see PSG as title contenders based on their current form, but there's no harm in hoping Chelsea can also win the title. Remember, Atalanta silenced Leverkusen when they were in very consistent form, and Chelsea now has that hope.
There is always hope for Chelsea in the midst of facing challenges against PSG. Even though they are a strong team, Chelsea has read all the movements with the extraordinary speed of PSG players and all Chelsea needs to do is determine or block the movement and that is one of them to break the opponent's players, even though it is not as easy as when facing them directly, I am sure Chelsea has observed all of that and a better chance can be achieved.