No it's speculation, I certainly don't agree that getting 41% Brexit will stop anyone even standings pro EU and meaning inevitable victory. I think what happens to UKIP depends on the Tories , if in wins I suspect they will lose a fair number the right and UKIP will strengthen , if it's close it could be a bloodbath first. If Brexit wins then the short term harm and negotiation challenges will mean a really big backlash from the centre but also an anti European hardening on the zealots and who knows who wins that, it depends who the angry sheep want blame next