Provide an argument for remain based on real world facts and/or data,
Sure. We retain a stable economy by remaining part of the largest free trade bloc on the planet. We retain the influence we have on the global stage as part of the EU. Given our population size and the size of our economy, we effectively share the leadership and direction of the EU with France and Germany, so we have far greater influence within the EU than nine-tenths of the members. Much of this is determined through the Council of Ministers, where you can see that in the ten years prior to 2016 decisions went our way 87% of the time (a figure which any British government would have been proud of in Westminster over that same period).
i.e. no opinions and no FUD?
Now you provide the argument for leaving, based upon real-world facts and data, without resorting to opinion and FUD.