London is crowded and an old city, so will not fare well during the coming shift which will be far more severe than prior shifts. The British Ils in the past have received jolts, to the extent of tumbling some of the Stonehenge massives, this will be at least as strong. Add to broken buildings and bridges the issue of old plumbing and sewage, and you have a mess. To the extent that London is above 700 feet above sea level today, it will remain above sea level after the poles melt. However,
crowded with desperate survivors, starving, this place will not be any more pleasant than other cities during the immediate Aftertime. Best to locate to rural areas prior to the shift, and plan on ocean fishing as a prime food source.