Columbus made a voyage to Bristol in the UK and certainly came across merchants who had travelled in the northern reaches, Iceland in particular. It is suggested that he did indeed travel to Iceland although the source we have for it is quite a few degrees removed from Columbus claiming it.

The Vikings/Norsemen had already spread awareness of Vinland to monks in Iceland, as the sagas regarding Vinland were written down about 100 years before Columbus visited Bristol. Did Columbus or other merchants in the North hear of these sagas? Did they come into contact with the written versions of these sagas?

Italian merchants had a serious incentive to find alternative trading routes.

There is a deeper question of why a man would go on a theoretically suicidal voyage, and on top of that, be funded by royalty to do so. Believing in your miscalculations is courageous I suppose, but its your life at stake; would a pious man be willing to kill himself chasing possible alternative geographic calculations?