Nothing is set in concrete. An independent UK would have a lot more flexibility to develop a closer arrangement. Why not negotiate trade and visa arrangements with the US rather than Europe?
As I noted above, people tend to limit their thinking to the current reality rather than what could be.
I am just worried that a majority both sides of the Atlantic want the philospher kings to rule if you saw my discussion with Scaniaboy.
One of my favourite thinkers said something like this:
Predict one year I can do it well, predict 5 years I can do it ok, predict 30 years I would have no idea.
Think it was Drucker.
Obviously my paraphrases of his thoughs.
Almost the most important question within such societal turmoil is how to act yourself within it. Your family. Your children.
One place where European and American conservatism are a bit different (I think) is that Burkean conservatives keep in mind the bond between generations. Our ancestors brought us here, here we are, let us make sure our children can have it as good or better.