I also like to collect the stamps, and have never been turned down when I asked for the stamp.
In the early 90's the Dutch immigration people at AMS always waved me through when I presented a Canadian passport and I had to hand it to them and ask for a stamp. I don't think I've ever been waved through on more recent trips, they all seem to have tightened up a bit.
Just ask for the stamp when you enter Canada and they'll be happy to give it to you.
Enjoy your trip.