The only workable future is for a no-deal Brexit to happen, and,

1. Northern Ireland secedes from the UK and joins Ireland as a single entity and stays in the EU,

2. the British economy tanks,

3. an exodus of foreign-born workers crashes the NHS,

4. unemployment skyrockets (think Thatcher-ite 1970's, with 40% of the population on the dole)

4a. an exodus of Brits to Ireland and the EU is stopped by more stringent visa requirements for Brits

5. the EU slowly negotiates new trade deals with the UK

6. Scottish Independence vote comes within 1,000 votes of passing, but fails again

7. the UK is utterly dependent on the US and EU for food subsidies

8. the EU slowly rebuilds the UK, through loosening fiscal controls against EU countries working with the UK

9. over about 15 years, the UK rebuilds through innovation in energy and digital technology

10. in 20 years they vote to join the EU.

11. in 25 years their GDP sees levels not experienced since 2015, and the population is 25% smaller than October 30, 2019.

If the UK fails to exit the EU, there will always be a shadowy "terrorist party" within the UK of Brexiteers who remember the methods used during The Troubles and will apply them liberally across Britain.

The only possible future is for Hard Brexit to happen, and fail. Anything else will lead to death by a thousand cuts.