Hello Theo

@media only screen and (max-width: 1466px) {

       .hero-title, #page-nav .next-hero-title {

              font-size: 11vw;
              line-height: 14vw;
       }

}

.hero-title {
    font-size:10vw;
    line-height:13vw;
    font-weight:500;

}

.hero-subtitle {

    font-size: 24px;
    font-weight:500;
    line-height:36px;
}

change the values for font size and then add the code to customizer -> additional CSS

in case you also need the size of the info text

.hero-text {
    font-size: 36px;
    font-weight: 400;
    line-height: 52px;

}