Things might get really interesting if Chelsea bring the right manager for themselves. But there isn't a definition of this in me yet.
They need to make their choice wisely about a manager. I mean that they should be careful about the strategies and tactics of that manager. If they don't match Chelsea then there is no meaning in signing him. I know that they are in a critical time period now so this is exactly why they should be careful with their choices as of now. Their chance against Real Madrid will still not be high though. But if they sign a solid manager then they can at least fight harder in this round against Real Madrid. Nagelsmann seems to be one step ahead now.
Chelsea really have a lot of great players who can build a strong team. But currently the Chelsea team can be said to have completely lost their rhythm. But agree with you, maybe if a new coach is added to the team, the team will regain its strength with new tactics.
Changing coaches at this moment I don't think is promising for Chelsea to improve their performance for the better and also, the fact is Potter is under contract for quite a long time. So, I think it's impossible for Chelsea to sack Potter at this moment because after all, with a long contract and it's still Potter's first season, I'm sure these factors will not make Chelsea plan to sign Nagelsmann.
Anyway, Chelsea should have been able to accept and deal with situations like this because after all, the results they are getting now are the result of the changes they have made and they didn't just happen. So, whatever Chelsea's plans are at this moment, I personally still believe that Chelsea have no chance of beating Real Madrid.
I think changing the coach can be working for any team if they chose a suitable coach for their team just like Bayern Munich and Tuchel. They hired a coach and they performed much better against Dortmund. Regarding Chelsea, they fired Potter finding a new coach who can help this team is a real pain for them, they should be thinking about a coach to help them have a better situation for the rest of this season and then invest in him for next season.