Nobody does because this is called second guessing the future.
But what is sure is that there will be a settlement either way. Both possibilities will allow for continued prosperity, though staying in the EU means agreeing to the continued erosion of UK sovereignty.
Germany and France will find a way of continuing to export to Britain without nailing us to the floor. They need us to prosper. In consequence they will allow us to export there.
But we certainly need to regain control of our borders and decide for the interest of the UK who we should let in, let alone that our own senior court administers Human Rights and so forth.
There are admirable countries that are intimately bound in trade with the EU but not members, who benefit immensely from not being tied to EU challenges to the absolutely sovereignty. Norway and Switzerland for two notable examples.
The EU may be annoyed by a Brexit, but it is in their interest quite as much as ours to preserve employment creating opportunities with regard to open trade,
ATB from George