Considering they have a working chip and the amount of orders they have been bringing in before they even had a working product, they would have no problem finding additional VC funding at this point. A start up project being literally sold out before you even have a prototype is almost unheard of.
Had the chip on the other hand been a bust and needed a complete redesign then this discussion would have been a lot more interesting. The only thing atm that could be a bit worrisome is the actual cost of making each pre-order unit, this is more about how fast they can make back the initial RnD costs though.