Honestly, I wouldn't mind doing away with cell phones entirely, or making them optional like in TS2, because those incessant calls and texts annoy me even when my sims are at home, let alone in the deep jungle...
I can think of one possible solution, even if it's not perfect: Do your Selvadorada tourists usually stay in the holiday homes next to the jungle entrance? If yes, how important are power and running water to you in that situation? Because I think (although I'm not entirely sure) that the off-the-grid trait affects the entire neighbourhood while you're on a lot that has it, and most of the jungle is part of that neighbourhood, so that lot trait should protect you from unrealistic calls there at least.
