I was able to get two lines with this CSS
.fc-daygrid-dot-event {
align-items: baseline;
}
.fc-daygrid-dot-event .fc-event-title {
text-overflow: ellipsis;
display: -webkit-box;
-webkit-line-clamp: 2;
-webkit-box-orient: vertical;
max-height: calc(2 * var(--line-height-large));
white-space: normal;
}
Any more than 2 lines and it distorts the day cells too much (even with two lines there’s a slightly perceptible distortion). align-items: baseline ensures other values line up nicely with the title.
With that additional CSS, the title has two lines, like this:
Bear in mind it will impact if you have two events on a date, like so:
