We are arriving at Heathrow Airport this Saturday 8/19 at 11:25am. We want to take train to Portsmouth and are trying to figure out how to do that.
It sounds as though we should buy tix ahead of time, but we are worried about buying tickets and missing our train due to (the seemingly inevitable) possible flight/baggage delays or problems. Will we have a problem getting tickets at Heathrow? Or, if we buy tickets and miss our train can we use those tickets for the next train?
Would love any advice possible! Thank you so much.