Actually Dazz, there are only a few DMPs left in Mexico. Since your fiance was in Cancun, there use to be one in Merida that he could have gone to, but unfortunatly they took that out
Heres the DMP list for Mexico. Your spouse has to get his medicals done before you submit the application, if you dont have it they will put your application on hold or just send it back from mississauga which will cause you a lot of delays.
Here are the
only DMPs your husband can choose from:
http://www.cic.gc.ca/dmp-md/medicalinfo.aspx?CountryID=2041&CountryName=Mexico
So essentially, Monterrey, DF, and Cuidad Juarez are your only options.. From Cancun I reccomend Volaris/Vivaaerobus to fly, with enough anticipation the flight will be somewhat economical.
I lived in Cancun and my spouse is from there as well. Quiet a few of us are familiar with Cancun and area.
Congrats on your engagement and welcome!