Andrew
I don’t know how it works in Canada, but here in the USA, I have shipped many karts using FASTENAL, GreyHound, Iship.com, Uship.com, etc.
Very simple, Just strap the kart to a 6×6 wooden pallet, then build a create around it so that it’s all protected. Then drop it off at the nearest terminal. I don’t know how the customs work for you, but if this shipping is locally in Canada, then it should be easier.