Hyperbole.
We are too big an economy for countries not to do trade deals should we exit the EU.
True and not true at the same time.
We are a big economy. No doubt it would be in the interests of the EU to have a trade deal with us. But it would be in their interest to have a trade deal with China, the US and India moreso I would think. So those things would probably be higher priorities.
The question is also what the terms of the deal would be. As good as we get currently? Unlikely. Unless we also agree to accept the things that people want to leave the EU to avoid.
About half of UK exports go to the EU. While a deal is worked out those would all be at risk. We'd also put at risk the portion traded via EU agreements. We've just put in place a FTA with Korea for example. It significantly reduces the high tariffs on Scotch whisky as just one example we leave the EU they go back on no doubt. And now someone from the UK government has to negotiate a deal with Korea.
on the other end, EU countries would stand to lose too. But they're risking maybe 4 or 5% at worst of their GDP. Probably a lot less for some countries. Now in a deal where someone stands to lose 50%+ of their wealth and the other 5% or less who is going to blink first?
Also consider what the practical solution to the issue might be. We vote leave and Cameron goes to the EU and what will he say? I'd bet something like 'how can we preserve as much of what we already have with the EU?' and the EU will probably say 'keep following all our rules, keep paying us money (maybe a bit more for good measure), just like Norway and you can still play'
Or do you send in a Farage to do the job? And alienate the people we are trying to do deals with?
How exactly does all of this play out while the economy suffers, people lose their jobs and companies move out?
Do you think that banks, multinationals and exporters are going to sit around and do nothing while the rough economy plays out for a few years in the hope of jam tomorrow?