Cabot was already on the way to North America while Columbus was still in the Caribbean.
But, if that's so, he had already returned from the Caribbean in 1493 (Columbus' first voyage), and proclaimed his discovery to the world. If he was at sea, it must have been on his second or third voyage.
That doesn't mean we cannot deliverately create a scenario in which Cabot's journey is the one were America is discovered. I just wanted to say that, IOTL, Cabot's journey had a lot to do with news of Columbus discovery, and may have not existed otherways. One can write a timeline or devise a scenario saying, as you do, "Cabot discovers America in 1947". But it's not right to assume automatically, as I've often seen it, that "
no matter what, even if there's no Columbus, America get discovered by Cabot in 1497". Because there might be no Cabot journey if Columbus didn't find
something first.
As wikipedia puts it,
"
Like other Italian explorers, including Christopher Columbus, Cabot was commissioned by another country, and in Cabot's case it was England. Once Henry the Navigator began searching for a route around Africa, the Iberian peninsula (Portugal and Spain) began to attract Italian navigational talent, especially after Columbus's discovery of "the Indies" (as all Asia was called at the time) by sailing west. After that voyage, a number of explorers headed in that direction; Cabot had a simple plan, to start from a northerly latitude where the longitudes are much closer together, and where, as a result, the voyage would be much shorter"
Of course, on the other hand, England could count on the Vikings' accounts to know that "there was something out there". So, in a way, she might have thought there were less risks in backing such an expedition than the ones Spain assumed IOTL, and end up backing it.
As for Columbus and his well known error, if it was not deliberate, once someone comes back proclaiming the discovery of land his error, correctly seen as such by learned men, his claim suddenly looks much more fortuitous.
Certainly.