I really haven't followed the Brexit story in any detail at all, except that I was applying two excellent and reliable rules of thumb:
the rabid Right, and the anti-regulation, must have small government at any cost ideology tank (it's not really a "think tank",) IPA was thoroughly for it; and
Krugman thought it a bad idea, while acknowledging at the same time the problems of the European Union as originally established, and saying that the economic downside won't be quite as bad as some claim.
It is therefore a certainty that the vote outcome is not a good thing.
Krugman's nuanced view is well worth reading (see last link.)
Also, it's a tad ironic, or something, that the Right took advantage in this campaign of a refugee crisis that is essentially of their own making. If it weren't for the fact that socialism is perfectly capable of still conducting fantasy experiments that cause economic and social disasters (see Venezuela) the "street cred" of the Right in terms of experiments it's been willing to try has been taking a battering in the last decade or so. But some idiot somewhere is usually still giving nutty economists grounds to point and say "ha! Look at how bad Leftist experiments are!"