I don't think that it's a good idea to have cash savings in different currencies, unless you know which will be the direction of the wind for that currency. You can suffer a lot of volatility and losses if you just convert your savings to another currency without knowing anything about which direction that pair will take.
Today we can see Brexit, but this is a fact that has been discounted by the market, so the currencies are already adjusted to that fact, but we don't know what will happen in the future, maybe Trump will collapse the US economy, or some other economies in Asia will raise to gain more leadership.
If you want to invest in an economy, I think that it's a best idea to invest on companies that are working in that country. This is a way of moving your money to other currencies, and at least you can see how is the company performing.