This is the first defeat of the season for Tottenham, so I think this game will not affect their morale and their game in general, everyone has misfires and it is unrealistically difficult to go the whole season without defeats. Chelsea in turn outdid themselves, it was a willful victory, but whether it will continue is far from certain. Now they have two tough matches ahead of them and if they win or draw, then we can say that Chelsea are on the mend. Although I still don't believe that they can get back to their previous level
I agree with you that Chelsea's last win cannot be used as a benchmark because they are in a better position I mean playing against 9 players if that is a normal match maybe the results will be different, as you said if Chelsea are able to go through the next 2-4 games without defeat, it can be said Chelsea in a positive trend. I personally doubt Chelsea can get 4 points in the next 4 matches unless they get the same luck as against Tottenham, but we know that luck does not come at all times and can't always hope for that situation.
This season the fight for European League tickets seems more interesting than the Champions League ticket, we already know which teams will secure UCL tickets but for the European League Premier League teams have many competitors including Manchester United, Chelsea and Newcastle there is also Aston Villa who is still consistent which can sometimes surprise the opponent.