An update: After much consideration and anxiety, I decided to change my departure time from Kings Cross yesterday. But alas it was neither easy or problem free. As I don't live in the UK, I had made the original booking via the Virgin East Coast Website. I followed the instructions to amend my original booking, trying to obtain a "Advanced Super Anytime" ticket, which, thanks to your advice, which would give me multiple choice of off peak trains. Unfortunately every time I tried to proceed with payment, it would comment "Not enough time for deliver, please choose another delivery option" I assumed that the orginal booking was done online, and I used the free "print" option, could do the same with this ticket. I called the London office at my expense and asked what was going on, and the operator advised me that probably couldn't do this, and best just to book another ticket and return the original one for a refund for a grand total of around 2 pounds. Obviously that wouldn't be worth it, so I persevered, trying the Advance Anytime with choosing a particular train, it worked up to the point of delivery, and again, I couldn't go further. Finally after two hours, I managed to change the original ticket to a later booked train at 2 p.m. I could not get a Anytime ticket. I am hoping that with 4 hours I should have enough time, but hey, who knows? My original cost of the journey would have been 3 pounds on my Oyster card. I have now spent, nearer 60 pounds as I have bought a Heathrow Express ticket just to get to my family. I have written, as suggested, to National Rail, Virgin East Coast just to advise them of my adventure. Not sure what good it will do, but I do appreciate all your advice. Wish me well!