To bring or not to bring all action cameras, regular cameras, and cell phones? How about just one? Well, that's entirely up to you and the dynamics of your production set-up.
Have you ever recorded outside or used your device on a nice day, but the temperature took a toll on your device and overheated? I record outdoors often and that's the first thing I learned -beat the heat!
Quality mics that serve their purpose without spending too much before you start monetizing your content. Oh yeah, use your phone. A quality phone with good storage works just as well as other content creation devices!
Just when you think everything is fine, your surprised by your device draining quickly.
It's better to be safe than sorry. Keep in mind that your homebase devices might not be universal or equivalent to power surges at your travel destination.