Travel between Brittany and England

I'm trying to determine how quickly someone in 1478 who wanted to travel from, say, Southampton to Vannes could do so, and I'm wondering if, because of the vagaries with winds and the like (which could trap ships in port for weeks at a time), it might be better to sail from Southampton to Caen, then travel overland through the formerly-independent Duchy of Normandy (which by this time was more or less securely under French control; the Norman ducal ring had been smashed in 1469 on Louis XI's orders) to Brittany.

Would it be easy or advisable for someone wishing to go to Brittany to do so overland, or would the Normans and/or French stop them from doing so?

Tamara