In uploader.php, adding the “folder” option seems to do the trick, but maybe somebody from Cloudinary can comment in case this has unwanted side-effects. If not, making this a configuration option would be great.
class CloudinaryUploader {
public static function build_upload_params(&$options)
{
$params = array(“timestamp” => time(),
“folder” => ‘wp’, // Specify Cloudinary subfolder here