As far as i know, the immigration office will mail the maple card to your Canadian address you offer to them when you first enter the country. So you can come back to China and ask your friends in Can to re-mail it to you after they get the card. But before I landed last year, a new immigrant was asked to take the card himself but he was back to China already......Woh.....that is really a big problem for him!! Who knows what has happened! So for the sake of safety, i stayed there until I got the card, then I immediately flew back to China to handle the belated jobs....
By the way, it took me 3.5 weeks to get the card.
The obove experience is just for your reference. It may vary from case to case.
Dan