I quizzed our pp lady while there getting estimates for shipping the other day.
For packages coming from the states Canada post can track them by the customs number once they enter Canada. You have to call in though it doesn't work to put the number in yourself.
One thing I didn't realize is that all our packages except letter mail include $100 insurance on them. Makes me a bit less nervous mailing things out without being able to get dc.
Not sure how it actually works but better than nothing.