Statistics Canada tells us how many Americans enter Canada either by automobile, plane, or "other" each month. In every province except Nova Scotia, "other" is not the most common. In the winter Americans are only flying to NS, and it seems like they're driving there less and less during the summer these days. So, are Americans typically walking to NS? That seems unlikely... Biking?
In Google Maps the directions for biking from Boston to Halifax instructs you to bike 211 miles across the Atlantic:
That 39 h bike ride is likely plus/minus a few hours depending on whether you bike on the ocean surface or on the ocean floor. I'd probably just stay home.