Was gifted a trip to Warner Bros Studios for Christmas for the whole family. I'm slightly worried about the timing of same. We arrive in London Heathrow at 9:15am and our slot for HP is 10:30am. I'm looking at travel time between the two at that time of day and it is saying approx 35 mins. What is the best way to travel to the Studios. Can I walk out of the airport and get a taxi for 5 people with ease. Should I book in advance and if so any recommendations for a cab company? Appreciate analysis tips also. Thanks in advance. The trip is next Thurs, 4th of Jan.