"So I suspect the idea is to leave the EU and then try and negotiate a deal - which I am willing to bet - will include aspect which will remarkably include a lot of the things people have argued about for the last three years."
I think the idea is more to crash out and create chaos, then to win a majority at a General Election thanks to idiot populists, then to have a massive bonfire of workers' rights, environmental regulations, and human rights while reconstructing the economy along ferociously neoliberal lines... and the idiot populists will STILL find a way of blaming immigrants for problems that are structural and economic in nature.