Big fan of Uber, but I've only used it in the US. I am landing at LHR next Sunday at approximately 10:00 p.m. Based on my research, public transportation options are limited late Sunday nights, and start to discontinue between 11:00 and midnight, and I'm assuming I won't get out of customs and have claimed my baggage until around 11:00 p.m. Thus, I'm hoping to use Uber. Has anyone had any success with Uber without cellular service and using wifi only? My previous experience with Uber is that the driver often has to call to pinpoint my exact location, especially at an airport.