wc-redirect-closed-store.php

// Add to functions.php if you want a redirect to happen when the store is closed.
// Comment out when store needs to open again
add_action('template_redirect','store_closed');

function store_closed(){
	if (!is_admin() && is_woocommerce()){
		wp_redirect('/store-closed/'); // Change store-closed to permalink you'd like to use
		exit;
	}
}