Man, looking at the table it's possible for another El Classico this season, if Barcelona and Real Madrid do make it to the semi final or final depending on grouping, but to be honest the numbers of potential El Classico are quite a lot this and it's getting exciting again with the likes of Raphinha, Yamal, Lewandowski, Vinicius Junior, Mbappe, Rodrygo and Jude Bellingham giving good performance in most games. I would really want to see another El Classico in the Champions League this season, though Barcelona has find it easy to trash Real Madrid twice now.
Too early to call this. We are now getting into the no nonsense part of the tournament! I think both teams have a long way to go before they meet. Barcelona may have been impressive in the domestic league and the Supercopa de España against RM, but never underwrite Real Madrid in the Champions' league (this is an unwritten rule 
)Also, I think Barcelona are still relatively doing well in their champions league matches till now and somehow I won't be really shocked to see them get there but like you said, it's the Champions League knockout stages, any mistakes or poor performance can likely knock them out.