I'm surprised backpacking isn't a more common answer. Pretty much every time I go backpacking, I'm essentially isolated from the world. My phone is just a camera/reference device at that point. Like you, I spent a few months backpacking before smartphones, and it was amazing.

I ended up losing my camera charger too, so I had to sketch everything I saw in my journal. I got pretty good at it, and realized how much more methodical, thoughtful, and slow sketching is, compared to photography. It was an enlightening experience. I bet you treasure your journal a lot. I certainly do.