Battery life while roaming out of the country.

Hello everyone, I will be flying out of the country this weekend. My cellular plan includes roaming.

My question is, I need some advice on how to maximize battery life while out of the country. The house that I am going to stay in does have Wi-Fi, it is just that when I am out of the house I would want to know what I would need to do to maximize my battery life? I have an iPhone 15 Pro Max, and it has 5G, should I possibly turn 5G off while out of the country? What other advice would you have so I can save battery life as well? I obviously will be downloading Podcasts so I can listen to them while on the plane, and I also will be taking an iPad with me as well. So I will definitely be downloading quite a bit of podcasts so I can listen to them while flying.
Any advice would be very much appreciated, thank you very much.