Hello! We need to get from Attleborough to Heathrow airport one late afternoon/early evening in late July. It's about 3 hours 15 minutes for the trip. We have a room booked at the airport, at terminal 4. It's a Holiday Inn Express.
Which train website do I use to buy an advance ticket? Or maybe I don't need to buy it in advance?? I'm trying to use raileurope.com and when I choose departures about 4:30 or 5:30, I keep getting warnings about 'Short interchange: Only choose if you're confident you'll have time to change at Cambridge and Farringdon' or other warnings that list other stations with short change times. I have no idea if I can make these short change times. Can a person with good mobility make these short change times? (Some are listed as 11 or 9 or even 7 minutes) Any other site I should use? Which one is best? Or just show up and buy a ticket when we want to leave?