Twig template suggestions for paths such as page--node--page-url

You can add suggestions for the page template in a hook:

mytheme.theme:

/**
 * Implements hook_theme_suggestions_HOOK_alter().
 */
function mytheme_theme_suggestions_page_alter(&$suggestions, $variables) {
  $path = \Drupal::requestStack()->getCurrentRequest()->getPathInfo();
  if ($path != '/') {
    $path = trim($path, '/');
    $arg = str_replace(["/", '-'], ['_', '_'], $path);
    $suggestions[] = 'page__' . $arg;
  }
}

This is an example how to add a suggestion with the path for any page. You can narrow it down to the pages you are interested in and if necessary check for paths that are too long.