Overwriting the menu break points of twentysixteen in child theme

Copy the js folder of the parent TwentySixteen theme to child theme root. Then add the below code in your functions.php–

function the_dramatist_dequeue_scripts() {
    wp_dequeue_script( 'twentysixteen-script' );
    wp_deregister_script( 'twentysixteen-script' );
}
add_action( 'wp_print_scripts', 'the_dramatist_dequeue_scripts' );

function the_dramatist_twentysixteen_scripts() {
    wp_enqueue_script( 'twentysixteen-child-script', get_stylesheet_directory_uri() . '/js/functions.js', array( 'jquery' ), null, true );
}
add_action( 'wp_enqueue_scripts', 'the_dramatist_twentysixteen_scripts' );

Then in your child theme js folder (the folder you copied earlier) find the functions.js file and make your changes. It will give you the desired output.