Just a minor update, but I'm officially in Latin America now. As for film handling, I have a bunch of 35mm, Provia 100/400x, Efke 25, Acros 100, Velvia 50, Ektar 100. It is stored in ziplocks that I keep in the fridge in my truck. I thought about the insulated cooler but there wasn't space. In any event, the fridge has been very reliable. I have solar panels on the roof of the truck to keep the battery charged and it runs 24/7, unless I'm in a climate controlled hotel (rare but it happens) in which case I bring it inside with me and shut the fridge off. If the fridge were to die, the six pack can act as a cooling buffer until I get it working again
I still haven't decided how to handle processing. I think local processing in big cities is the way to go and I'll be looking for specific recommendations as I travel. Otherwise, I'd ship it back to the states via FedEx or DHL. I wish I had some way to guarantee it wouldn't get x-rayed as cargo but I haven't been able to find much specific information on how to do that. Local information is not trustworthy, IMO.
I can say that my one experience with the Mexican post has not gone well - I had some parts for my truck shipped to me from the states and they disappeared in the hand-off to Mex Correo.