Doesn't change the fact that on the world stage, we are pretty much irrelevant now
Our position is waining for sure, but irrelevant? P5 UN Security Council, Founding NATO member, G7/8/20, Commonwealth, US "special relationship", Nuclear Subs (if we renew Trident), and we haven't lost the financial power of The City, yet.
As much as I voted Remain and firmly believe we are better within the EU, I'm also something of a realist - there'll be a period of readjustment and our position on the world stage will be lessened (hard not to be), but we will survive. Give it 20 years or so post Brexit and we'll have our economy and position on the world stage suitably refocused.
The most important thing to us right now is London. It is the de facto capital of the world. If we loose that then our position might be in serious jeopardy.
I think we'll end up with a fudged token Brexit. We'll be full members of the EU in all but name and voting rights.