As per theme design and header structure logo size is best suitable as per our demo site, but you can change logo size if required using custom CSS.
General Option: Navigate to Admin > Appearance > Theme Settings > General From Admin Panel’s Sidebar and then add below mentioned custom css with your desired max-width in CSS Code textarea field and save changes.
.logo {max-width: 109px !important;}
If you want to change footer logo size then you can use below css code with your desired max-width value:
.footer-logo img {max-width: 100px;}