Dynamic widget areas

customize.php

<?php

/**
 * Register setting and control with the Customizer.
 */
function dynamic_customizer_register( $wp_customize ) {

	// Add setting.
	$wp_customize->add_setting(
		'dynamic_widget_areas',
		array(
			'default'           => 5,
			'sanitize_callback' => 'sanitize_text_field',
			'type'				=> 'option',
			'transport'   		=> 'refresh',
		)
	);

	// Add control
	$wp_customize->add_control(
		'dynamic_widget_areas',
		array(
			'type'		  => 'number',
			'label'       => __( 'Front Page Widget Areas', 'theme-name' ),
			'description' => __( 'Select the number of widget areas to display on the front page.', 'theme-name' ),
			'section'     => 'static_front_page',
			'settings'    => 'dynamic_widget_areas',
		)
	);

}
add_action( 'customize_register', 'dynamic_customizer_register' );

front-page.php

<?php

/**
 * Dynamic front page widget areas.
 */
function dynamic_front_page_widgets() {

	$front_page_widgets = get_option( 'dynamic_widget_areas', 5 );

	// Loop through and display widget areas.
	for ( $i = 1; $i <= $front_page_widgets; $i++ ) {

		genesis_widget_area( "front-page-$i", array(
			'before' => "<div class='front-page-$i'><div class='wrap'>",
			'after'  => '</div></div>',
		) );
	}
}

widget-areas.php

<?php

// Conditional variable of front page widgets. (Dynamic widget areas workaround).
$dynamic_widget_areas = is_customize_preview() ? 20 : get_option( 'dynamic_widget_areas', 5 );

// Register dynamic front page widget areas.
for ( $i = 1; $i <= $dynamic_widget_areas; $i++ ) {

	genesis_register_sidebar( array(
		'id'          => 'front-page-' . $i,
		'name'        => __( 'Front Page ', 'theme-name' ) . $i,
		'description' => __( 'This is the front page ', 'theme-name' ) . $i . __( ' widget area.', 'theme-name' ),
	) );
}