I am a wagon master for an RV caravan company in Mexico. There is a whole section in their orientation manual on this subject. It starts on page 20. And yes, you do have to be careful about power in many parts of Mexico. That document also contains a lot of other useful information. Here is the link
https://mexicocaravans.com/caravandetails.pdf
You might also consider signing up for their newsletter if you are going down there
https://www.mexicorvbuddies.com/newsletter.php
I have never seen a 220v supply for RVs anywhere in mexico. Most are 15 amp, some 30, only a couple with 50 amp. All 110.