I’ve never been a believer in “the golden horde” theory, especially not in the UK, the British aren’t made that way. in a serious SHTF event where the power goes off and there is no petrol or diesel available I really don’t see Brits walking very far, yes there will always be exceptions but they will be few in number. and where will they go? wandering aimlessly is liable to get them killed very quickly. as I said I cannot see many people leaving, they have spent too much money on their houses that they will be disinclined to go far, more like scavenge within a few miles of home and then return there each night after a days scavenging. Brits are more inclined to complain to the government-if it still exists post SHTF, after all the most popular saying among the UK population is “the government will save us”. most believe nothing bad will ever happen so by the time they realise something has happened(I expect a domino or cascade event rather than one big bang) it will be too late and they will be too weak to go much further than the end of the street. just my observations.