I don't disagree. But it was the same last year, the authorities have had two seasons to plan for this very likely eventuality.
Reduce the semi-final to one leg if there is no room to play the quarter-final without forcing a team to play two games in three days. Play the league game later in the season. December games get postponed all the time, it wouldn't be the end of the world. Start the league earlier to free up the midweek when we played Brighton for League Cup games. Swap the league and and League Cup midweeks around and arrange that they play a team not in Europe on the league midweek so can be played in the Champions League/Europa League week. Start the League Cup earlier. There are loads of solutions.