The usual suspect
No doubt when the UK goes to crap all parties involved in the making of this disaster will blame it on the EU and the other 27 countries in it. Especially the pesky Krauts that were unwilling to get those 26 others to rewrite the treaties that make up the EU and let the pea eaters have all the nice things they wished for. That after all is what they been promised by their Tory overlords and other madmen who are now expected to deliver. Blaming the EU having basically been the problem with in UK politics all the time as none of those were brave enough to go against the power of Murdoch for the past decades nor would they take responsibility for their own actions.
Now I wonder if there will be any that will be brave enough to avert certain doom this year, cancel Brexit to save the UK, make serious work of the EU and change whatever EU rules would be more prudent to try and do it all over once things got worked out. No doubt there are some populist in Europe that will gladly sow the seeds of future trouble by supporting the Brexit effort if only out of spite. There are plenty of fascist movements to support the destruction of the socialist abomination that is the EU.
If not I gather that illegal immigration to the UK will soon be a thing from the past and that mainland Europe and other horrible places can expect an influx of starving Brits and warzone refugees from the borderlands of Ireland, Wales, Scotland and Manx, much like in the olden days. After that period in which England is only populated with coarse peasants who have managed to survive the harsh realities of their cake, the wider EU if it hasn't been occupied by the Chinese yet, may attempt to recolonise the island and bring it back to civilisation.
Nah,... what probably will happen is that the UK will gladly flaunt any WTO rules about inspecting stuff at the borders, claiming to be incapable to comply due to a lack of customs officers and failed IT projects. And people have to eat, get their medicine and have holidays abroad. The cost of these legalities however seem to cost vastly more than whatever the UK ever contributed to the EU and just when you thought to have moved all the bureaucrats to Brussels they'll have to be reinstated at home.