As for marriage abroad... we got married in Slovenia and my husband needed something called "Statements In-Lieu of Certificate of Non-Impediment to Marriage Abroad". It's issued by Foreign Affairs and International Trade Canada, see
here. The processing time is 25 working days, so I'm not sure you can even get it in time. They'll need your birth certificate and a statutory declarition of yours stating you're not married.
Based on
this link, it seems you'll need the same thing. I'd recommend your fiance goes to check with whomever will be marrying you, it's what I did.