Brexit wont happen. All that is happening is pure political posturing at the moment. When it comes to the hard-ball negotiations, the whole concept of Brexit will be blown apart. There are simply too many complex factors against Brexit to allow it to happen and simply not enough clear factors in favour of Brexit to make it happen.
1. There is a legal challenge in the British High Court against the triggering of Article 50 without a parliamentary vote. Unlike Irish referendums (before Lisbon and Nice), outcomes in British referenda have no real legal standing. Even if this HC challenge fails, the House of Lords may scupper any Commons vote.
2. Scotland, the emergence of another campaign for independence and subsequent break up of UK may sway some Brexiteers from pulling the trigger.
3. Ireland, the prospect of a return to a hard border will collapse the Stormont assembly if SF are still in power. If SF administer a border (be it British, Irish or EU) within the 32 counties they may as well wind-up and go home.
4. EU, the notion of retaining full access to the free market without concessions to the EU in some form is simply dumb. It wont and cant happen without threatening the very existence of the EU itself.
5. No-one actually knows what Brexit is.
6. The Liberal Democrats have already stated they want a second referendum and will campaign to Remain
7. The Labour Party have said that anything less than a full Brexit, it will need to be put to the people again.
8. If Brexit was stirred by too much immigration, then it is worth noting that the largest cohort of immigrants come from the Commonwealth countries, not the EU.
The list goes on...but these points are to the fore.
If you have the funds, buy Sterling on the way down.