"but some shipping/logistic companies will have to move south, and then who will move our product to market"

this doesn't make sense on the face of it. If there's demand to move product (ie south) here that's a boon to canadian exports, and the lack of cross-continental shipping will make such transport cheaper, and more relatively efficient relative to alternatives, making a tighter internal economy

if there isn't, then the export of our logistic companies makes economic sense on its own