You would need to make a few changes and a little CSS.
Make the H1 responsive by removing the inline-css you have. And then set this in your Customiser > Typography > Headings. Set the Desktop to 70 and then reduce the mobile right down to say 44px.
Then you can adjust the mobile top and bottom padding in the page hero to about 10% each.
Then add this CSS:
@media (max-width: 768px) {
.page-hero {
background-size: 100%;
}
}