earlier discovery

Is this plausible or ASB: During the settlement of Iceland, it comes to be believed that it's the middle point between to large landmass and so a foolhardy expedition sets sail southwest from the western coast and arriving at the Grand banks just before their stocks run out and spotting land...

Pretty much what the title says. What would have happened if the English (or another European country) had sttled Australia at a time different from 1788? (even if there is no European settlement until the 20th Century!)