However, if Real Madrid fails in the Copa del Rey then it looks like this season will be a season of failure for Real Madrid who has the chance not to win any trophies this season. But yes, because Real Madrid is king, then of course Real Madrid will still be the favorites to win the title, whether in the Copa del Rey or in the Champions League but at this moment not with La Liga.
In the Copa del Rey, Barcelona has won 1-0, of course it is an important capital for Barcelona. But the Champions League, if you can win against Chelsea, then Real Madrid will face one of the best clubs this season, Man City or Bayern. So the chance to get the UCL trophy is also very small. Yes, it's possible as you said that Real Madrid will fail to win a trophy this season. And this will be a bad season for Real Madrid.
I see Carlo preparing young players for next season. He always puts young players first in every game. Even Toni Croos often sits on the bench. He always put Camaviga first, even though the midfield was often locked.
Maybe they can spend a single year without any cup at all? I mean that's not really a terrible thing neither, we are talking about Real Madrid here, they won so much in the past 5 years or so, just the fact that they have 4 UCL in such a small amount of time frame, in what 6 or 7 years or something? That alone is great and gives them a chance to just let it be. They can be bad this season, be gone out of UCL in semi finals, be second in the league and win nothing at all.
That's good enough if you ask me, I do not think that there is a need for anyone to be really working towards winning anything more. Just focus on the next year and be better next year, it is not a terrible to have just a single season with nothing.