The landing document only entitles you to come to a Port of Entry where an immigration officer will determine if you are eligible for landing. At that time, if you are still eligible to land in Canada, your US deportation order would certainly prevent you from re-entering the US regardless of your status in Canada. There is a requirement that all intending immigrants be able to demonstrate at the time of landing, that they will be able to support themselves. The amount required varies from Port of Entry to Port of Entry. I advise my clients that they should have at least 14,000 Canadian dollars per adult.
Proof can take the form of a current bank statement.
I appreciate your answer concerning my car. I am moving from Detroit to Windsor. Yes, again, the fact that you are a J-1 holder indicates that you are likely eligible. Once your landing documents have been issued, the validity date will not be changed except in a very exceptional circumstances. If you don't land, or can't land within the validity of the landing documents, you should return them to the issuing visa office in order to have your right of landing fee refunded.