I only know visits to England as part of the European Union, what we cranky Yankees used to call the United States of Europe, so I don't pretend to know what's "best" for the nation we fought a savage war of Independence to not be a part of.
I'm not sure what the right answer for the citizens of the United Kingdom looks like and how that answer impacts the rest of the EU and the world. We'll have time enough to worry about what it all means and/or doesn't, when we know what we don't know yet. Tomorrow and tomorrow creeps in this petty pace from day to day. Until it doesn't. So far, so good. So what now?