Apple TV is an internet streaming device. Not for offline. Netflix and Disney+ are internet streaming services. Downloads on mobile devices are allowed. But then streaming to a different device may not be. Netflix is known to actively block AirPlay (streaming or downloads). Not sure about Disney+ downloads.
«It just works» requires internet connectivity, because that is how it just works. Cable TV requires cable. Mobile phones require cell towers nearby. Electrical devices require a power grid. There is always a dependency, and you know that.
You could set up a personal hotspot on your phone, and let the Apple TV connect to that Wi-Fi. Note that the Apple TV will request a much higher quality stream than the mobile device would, resulting in much more data use (e.g. 20 Mbps = 9 GB/h). Depending on your mobile plan, you may burn through your monthly data cap in a few days. Even ‘Unlimited’ plans are not really unlimited. Check with your cellular service provider on what they allow, because they will monitor it.
The real solution is to bring internet to that location.