This makes sense. Thanks for the first hand experience. It always seemed odd to me that Jenny told JR about being out of wifi range, but if she had researched her possible route, it would be a kindness to warn him, rather than just go off the radar and leave him in panic mode. Unfortunately, that information slowed down his reaction time.
JMO
JMO
My guess is that she told him about possibly going out of wifi range because that is how they were communicating, and she did this while still with wifi.
I know that some online sites give 18 hours for the Oaxaca to Cancun drive, but I think that is very optimistic. My Lonely Planet guide book for Mexico gives 12 hours for Oaxaca to Villahermosa and 12-14 hours from there to Oaxaca. These are times for the public bus, and in my experience of having taken buses over these routes more than a couple of trips, you would be lucky to make those stated times. Jenny had figured on 4 days of hitchhiking to get from Oaxaca to Cancun (if I remember correctly?), so in my opinion she had done her homework and seemed to be planning on spending the nights off the road on her way.
The southern highway that crosses the Yucatan, through Escarcega and Xpujil, is sparsely populated with few towns of any size. I wouldn’t be surprised if there was no wifi and maybe no cell phone coverage in areas on that stretch of road. Maybe truckers would communicate with CB radios there. I could easily be wrong about this though, as all I am going on is what I have personally seen of the area. Jenny might have felt the same about the possibilty of loosing wifi there, whether correct or not.