Get a lease form from Grand & Toy, fill it out with your parents as your landlord, boom, you have a legally binding lease to return to.
Get a part-time job for the duration, and a letter from your employer stating you are on approved vacation leave and expected back on such n such date.
Just about anything can be used as proof of ties, not just jobs and mortgages. If you have obligations that are not easily abandoned without personal financial hardship (ie: paid tuitions, rent due etc) these will help.
Plus, letting them know that your future wife intends to immigrate to Canada and that you will be sponsoring her will definitely help. Fill out some of the paperwork in advance, take it with you and tell them you're taking it so you can complete it directly after the wedding and send it in asap.
In 2001 after 2 years of dating I went to the US with intent to be married, and no intent to stay (at the time my husband planned to move to Canada, that didn't work out
) When asked the purpose of my visit, I told them I was taking a very quick vacation to see my fiance. When they asked when did we plan on getting married and where were we going to live, I said "soon, and he's moving to Canada as soon as the paperwork is done". They waved me through and said have a nice trip.
Either way, it really is a crap shoot. Just be prepared, be polite, and be truthful, but don't run off at the mouth.
And if you've got a tuxedo in your carry on, don't lie and tell them you're going to a costume party as James Bond. 
