Britain should simply sever totally effective tonight at 0000 hrs. It can be done and will ultimately be cheaper, sooner, and a lot less complicated. I suspect that the PM and the establishment class will make it as difficult and onerous as possible in order to get another vote to reverse Brexit. Or they may use the negotiations and wrangling to essentially stay in the EU but change the names of some things, sort of like what the Republicans are determined to do with Obamacare. If Brexit is successfully sabotaged I expect Britain will lose the pound in the process and will turn over its financial control entirely to the EUSSR Central Committee.
Wonder why Farage is not getting involved???