Turn WP_Error into Catchable Exception.

gistfile1.php

<?php

use WP_Error;
use App\Exceptions\RemoteCallException;

function remote_get($url, $args)
{
  $result = wp_remote_get($url, $args);
  if ($result instanceOf WP_Error) {
    $errorCode = current(array_keys($result->errors));
    $errorMsg = $result->errors[$errorCode][0];
    throw new RemoteCallException($errorCode .': '. $errorMsg);
  }
  return $result;
}

try {
  $res = remote_get($url, $args);
}
catch (RemoteCallException $e) {
  echo $e->getMessage(); // http_request_failed: A valid URL was not provided.
}