At present, I do not feel Brexit is an impending threat. The government must hash out a satisfactory withdrawal plan before they invoke article 50. This could take many many months, and Theresa May might be coming close to completing this, but even with a withdrawal, the government cannot just throw people out of the country and I believe there should be something in place to protect EU and international workers, perhaps offering them preferential visas if their employer wishes to keep them, which many will. A mass exodus and deportation could crash the economy if not controlled.
But for now, it is a few years away and I believe we should allow a 'watch-and-wait' period to see exactly what our government come out with.