Transfer from Darjeeling to Bagdogra airport

I am looking for a reliable transfer from Darjeeling to Bagdogra Airport for my return flight, but I am worried about the steep mountain roads and potential fog delays. Is it better to book a private transfer in advance to ensure an experienced driver and a sturdy SUV that can handle the winding Himalayan descent safely and get me to the terminal on time without any last-minute stress?