Can I drive to Canada with a passport which has a a worn front cover?
That should not be a problem. The most important page in a passport is the data page, the one with your name and photo on it. If that is good, you should be OK. Regardless, I recommend that you get a replacement passport issued to you. The cover is intentionally made of harder, water-resistant material (many times it has a vinyl outer layer), to protect the inside pages. How the hell did you manage to destroy the cover alone?