I don't know for sure how many Real Madrid players will be out through injury until January, but losing Bellingham, Camavinga and Vinicius will have a negative impact on their performance. Barcelona experienced the same case due to player injuries, but currently most of its players have recovered even though they have to find their form again after a long absence.
Girona can capitalize on this calamity facing the other teams and make sure that do not loose any other games for the period and weeks tha Real Madrid will be struggling. There is a sense of teamwork among the Girona players, and a sense of possibility, so they can actually keep playing thos season without loosing any more games. Real Madrid's next game is an away game to 16th place Cadiz, that game should not be the game where Real Madrid should start loosing points.
Girona can even win the game against Athletic Club in the next week they have. But the fact about Girona is I think they are going to lose their place and this team doesn't have the enough potential to be at the top of the La Liga table at the end of this season.
Other teams with the much better players and more investments couldn't have this good performance and I'm wondering how a team like Girona can be in the first place in the league.