My research indicated that it takes about a hour to get from King's Cross to Heathrow and that Eurostar trains are usually on time. Based on this I bought round trip London to Paris Eurostar tickets. Our return train arrives at St Pancras at 9:00am and our flight back to the US leaves Heathrow at 2:10pm. I thought I would have enough time, but now I am seeing posts about how you shouldn't take the train on the same day you fly home. Is there any special reason for that? Am I missing something with the timing? My tickets are non-exchangeable, but if I really need to get new ones, it's probably better to do it now while discounted tickets might still be available.
Thanks for any feedback or help you can provide.