I have not tested this code but I think it might work. Add it to your theme's functions.php file.
function my_woocommerce_maintenance_mode($content) {
// condição para paginas do Woo. Mais infos: https://docs.woocommerce.com/document/conditional-tags/
if( is_woocommerce() or is_shop() or is_product_category() or is_product_tag() or is_product() or is_cart() or is_checkout() or is_account_page() ) {
// Mostra o que vc quiser aqui.
$content = "Em Manutenção";
return $content;
}
add_filter('the_content','my_woocommerce_maintenance_mode');
Maybe it's a good idea to hide the products using CSS if you've inserted them into some page outside the woo with shortcodes for example. Something like:
.products, .product {display: none !important;}
Some things I would take into consideration:
Do something so that Google does not index this "In Maintenance" page. It would be annoying the store's customers to search and in Google results only take on "Maintenance". And for this you can learn more about status 503 here: link
Maybe you want to leave this maintenance mode for everyone except you (site administrator or manager) and just add a condition like:
!current_user_can( 'manage_woocommerce' )
in the function created above.