Stanstead airport is about an hours train ride maybe a bit longer from London Victoria (that will take you into Central London, then you would have to make your way to the hotel)....and your hotel is quite a way out from the meet if the meets at Southbank.... from your hotel you'd have to walk about 10 minutes to a station called Newbury Park and get the tube to London Bridge, then you can walk down to Southbank....but if you haven't used the tube before, might be best you find a closer hotel, or stay with Tommy F