They will enjoy the EU until they get the bill. Seriously stupid, however, the breakup of the UK is now a possibility.
Guess what, though, UK are net importers with the rest of the EU, and by a long way. With such a large economy, and that the EU are economically stuffed as it is, the EU needs the UK for trade just as much as the UK needs to keep the trade status quo. 10% of total number of BMWs are sold in the UK.
UK trading with the EU is mainly with Germany + Netherlands + Norway + Belgium. What will most likely happen is that these countries will push for the UK to get special trading status to avoid tariffs. The issue will be that the UK WILL NOT formally ask to get this trading status because Brits will have to pay for it (which is what they're doing nowadays anyway) and relinquish some of its sovereignty, which we definitely know they will not do.
Either way they are contemplating a very ugly future. Scotland will secede from the union, the Sterling Pound will get pounded... Brits will not be able to buy ½ of what they're buying nowadays, et cetera.
I blame this squarely on how Merkel and the Germans acted with the Greece issues though. If there has ever been a fucking time Germany could've redeemed themselves from the ball and chains of the WWII, it was helping out the Greeks sort out their debt (the Greek government pardoned their debt with the Germans post WWII). Instead of doing that, Merkel embarked in a tour of PIGS that involved austerity measures the likes she wouldn't even DARE impose on Germans even after WWII. And Germans, being that they are fucking screwed up human beings, loved every second of that shit.
SOOOOOOO, it's no wonder Brits saw that and said "fuck this shit! This isn't a Union!". A process that culminated in what we saw this past week.