My guess is that after all the screaming and shouting is over pragmatism will kick-in - the losing side will have nowhere else to go except the political wilderness.
How that spans out will depend on whether the Corbynites fight hard to keep their power. They do have the votes from the members and if they don't care about the electability thing things could get very dirty indeed.
After the referendum UKIP will have lost their raison d'etre. If there is a BREXIT vote Douglas Carswell will rejoin the Tories but the rest of the party will just dissolve. If there is a REMAIN vote on the other hand, UKIP will be reduced to small groups of discontents muttering in dark corners.
Either way - no UKIP.
No, No, No, no, no.
UKIP are a party going from being a movement to a proper political party, hence all the upsets and in fighting.
The political landscape is changing which is a perfect opportunity for a new party to take hold of things. This referendum is just one part of the dissatisfaction that is running through politics in the Western world.
If it is a Remain vote then not only will UKIP keep on fighting on for a Brexit but many of the Tory lot won't let go of the fight. This passion goes very deep into peoples' hearts and it ain't going away.