What do you think a British high speed railway network would look like if work on it began back in the 1980s?

I'll say that in the early 1980s British Rail is impressed by the success of its own Intercity 125 and the first high speed railway lines in Italy and France so they begin research into the viability of a British high speed railway. They contract TGV to build it.

When the channel tunnel is commissioned, so is HS1. King's Cross, St Pancras and Euston are merged into one mega station. While HS1 and the channel tunnel are under construction, TGV work on plans for HS2 with the long term goal being to extend it all the way up to Scotland. To clarify, the British high speed railway is built to the same standards and rolling stock as the French one.

What do you think it would look like today? What route do you think HS2 would have taken in this timeline and how long do you think it would have taken to complete? After completing HS2 what routes would have been built next? Could we potentially see some long distance high speed routes such as Manchester to Amsterdam?