I expect that it will be a no-deal Brexit on the 31st October. And, the UK will be forced back to the EU within weeks to beg for a belated acceptance of the WA as negotiated by Theresa May. May will feel totally vindicated by that. But this will lock the UK into an absurd situation with NI, and (unlike now) it will at that stage become a truly vassal state, with no representation at the European Parliament, no veto, no nothing. We will have to accept whatever rules and trading positions the EU as our own (but with no say).