We will arrive 7 am from US and need to book train or bus ahead to travel to Bath. The problem is we don't know when we will be through customs (carry-on luggage). Train is more expensive, more frequent, but may be booked. Bus may leave us to wait til 11:30. Ideas?
It's a Sunday ...
I did this journey frequently when visiting family and always took the bus (coach). You need to allow at least 1 - 1.5 hours to deplane and clear immigration at Heathrow. Depending on which terminal you arrive at you will need to add on time to reach the coach station, near terminal 3, if you chose the coach. I’d take the time to freshen up, have a have a coffee and something to eat and maybe pick up something for lunch on the bus. The coaches are comfortable and it’s a pleasant drive to the West Country once you are outside London. I used to fall asleep for most of the journey!
The train involves either going into London or getting to Reading and picking it up there.
I also recommend the bus instead of the train. Enjoyed the ride though the countryside and smaller towns. I sat next to an older lady and we had an enjoyable conversation during the trip. It has taken me longer to walk from terminal 2 to customs and immigration than to clear customs and immigration with only carry on luggage.