Add this code to the Custom CSS field on the Appearance tab of your Google Maps widget’s settings:
.global-styles,
:root {
--width: 500px;
}
.global-styles,
.eapps-google-maps:not(.eapps-google-maps-small) .eapps-google-maps-bar-container {
width: var(--width);
}
.global-styles,
.eapps-google-maps:not(.eapps-google-maps-small, .eapps-google-maps-bar-opened) .eapps-google-maps-bar-container {
left: calc(var(--width) * -1);
}