For the avoidance of doubt, and for those who seem to have every knife and dagger aimed at the DfT/NR/TOCs at every opportunity possible... this has been planned thoroughly and the essentials are this:
There have been comprehensive, well attended, sometimes terse and frank, thorough, honest, sensitive, multiple all-day meetings on this project between ALL parties concerned. At one point there was a meeting with almost every single UK TOC represented in one room (aside from TfW, GWR, SWR, c2c and SE). I refute any claim that NR haven’t talked to the TOCs, vice versa, that it’s poorly planned or that it’s pathetic. This is a genuinely collaborative piece of work between TOCs/NR that I have never seen before.
This work absolutely has to happen and the length and distance the block covers is essential - there are no alternatives. The most significant worksite being undertaken is resignalling of the ECML to York ROC, but it also includes some work in Stevenage platform 5 and some work around King’s Cross. To say it doesn’t have to be that weekend, or that it doesn’t need to be so disruptive, is wrong.
Every single possible permutation of alternative routes has been considered and fleshed out in detail. If it was possible, it would be done. If it is not being done, it was not possible. For example, the offer was given for TOCs to loan stock to other TOCs for the weekend - some TOC execs approved some very interesting offers to loan units/coaches elsewhere, but these were declined for various reasons (driver traction knowledge, driver resource/cover availability, route clearance). Diverting trains on alternative routes into alternative terminus was also fully discussed, but there were caveats to that too (driver route knowledge lacking and failing that a severe lack of freight driver availability to pilot crews, lack of capacity on alternative routes, lack of platforms at alternative terminus, etc). And yes, AGA will be running longer trains, strengthening to 12 where possible and starting their Bishop Stortford to Stratford services back from Cambridge.
There are also a number of planned alternative travel opportunities (bus/coach services) - some of which will be advertised, some unadvertised to soak up extra passengers on the day - which are yet to enter the public domain.
The work must happen and the alternative travel options in place are the very best that the TOCs can implement. Hence the very strong message for the weekend is DO NOT TRAVEL. If you know people - friends, family, work colleagues, even spotters and enthusiasts - planning to travel that weekend, warm them now not to.