It looks like I don’t even require a guarantor signature on my application if my passport is still valid, or has been expired for less than one year.
Apparently I just need to list two references. Is this correct?
You’ll be doing the simplified renewal then? Because my old one expired more than two years ago, I had to do a complete application from scratch.
Cool. I’m doing the 10 year thing and then another ten year thing. I may or may not require a third extension, but if I do, that will no doubt be my last. 
Yeah, my problem was that the old one had expired for too long, and being in the US (at the time) I had a limited number of Canadians who had known me long enough. I’m still a little annoyed at my mother for not having a Canadian passport!
This time, I’m doing the simplified renewal, but I also have a lot more Canadians who can vouch for me.