SAN - LHR = 5500 miles whereas the range of a 757 at best is 4200 miles if it's been upgraded with winglets. So, yes it would struggle with the last 1500 miles or so in a glide.
If however you'd paid attention to the previous poster (ATNotts) and used the correct IATA code for the Sandford airport - SFB - your post might have a smidgeon of credibility.....
