well let me choose one of many.. my mind goes right away to an experience about ten years ago I guess when the ElanIIe came out. I bought two, to be on the safe side, and took with me another older Canon camera as backup. I used the cameras for several weeks without any problems.
Went to the Southwest and in Monument Valley, my very first day... the Elan IIe's did not work- a problem with the contact of the batteries I learned later--- the older Canon had a problem with changing lenses so I ended up shooting for 9 days, with one lens on my old old Canon AE. It was a pathetic sight indeed as I had hired a special guide to take me to an extensive trip to the Anazasi ruins...
Canon replaced the two cameras with new ones, but, who can replace the time, the cost of the trip and everything else?
My suggestion, travel VERY prepared for many unforseen circumstances..
Now, I am prepared and take backup cameras and ship everything I didn't need back home from one or two destinations. It's expensive, it's sometimes cumbersome, but, in most interesting places there are no supplies, no replacements, nothing at all.
Lots of luck