If you’re looking for something you can carry about and use to store data on, why not just a USB-C thumb drive or external SSD?
Edit; this is intended for photographers, but you can get external SSDs that create their own WiFi network so you can transfer files wiressly to and from them: https://www.westerndigital.com/en-gb/products/portable-drives/wd-my-passport-wireless-ssd?sku=WDBAMJ2500AGY-EESN
I’m guessing New Zealand.