We arrive the ungodly hour of 6:55AM and don't depart for our flight to Rome until 3:45PM that afternoon. We fly into Heathrow on American and from London on British Airways to Rome. I'd appreciate hearing from those that are familiar with that airport and its terminals to provide some information about terminals, etc. How long it takes to get through customs on arrival and through security prior to our outbound flight to Italy. And, finally, would it be feasible to leave the airport or do we risk the danger of getting caught up in traffic trying to get back to the airport for our departure? If we decide to not venture off, what's available to do at the airport and are there places comfortable enough to stretch out and take a nap if we dare. It would seem we only have about 5 hours of "free" time since it'll probably take over an hour after we land and get through customs, and we'll need to be at the airport (should we leave the premises) at around 1:30ish. Some suggest going to Windsor, but I don't believe we'd have enough time and we're never able to really sleep on an overnight flight anyway so we'll probably be too tired to try to rush around to see anything anyway.
Buy a day pass to the airline lounge, take a shower, and enjoy some decent snacks and adult beverages. More likely to find a quiet corner for a quick nap than in the main terminal waiting area
Probably no more costly than traveling to/from London and having the tension of wondering , 'will I get back in time?'
You could go to Windsor, which is a 15 minute cab ride from Heathrow. You could tour the castle, have a good pub meal then return to airport. You would need to be back to the airport between 12:00-1:00pm.
Some years ago, we were in the same situation. We got through customs, checked our bags, and went to the British Museum. You can either take the express train or the local. The Express is 2x the cost and saves you about 10 minutes. Take the local. We had enough time to tour the museum and have a pub visit.