How long can the Catholic Church be without a pope?

According to Wikipedia the longest papal election in the history of the Catholic Church was from November 1268 to September 1, 1271. How long can the Catholic Church be without a pope so that we can say that the succession was broken? If there is defined no length of time, then if simply we don't need a pope for three hundred years, we can wait that long to elect one and papal succession would remain unbroken.