I recommend you stay away from anything that requires any kind of portal to setup. If you have to download an app and create an account in order to pair the device or get it setup then don’t use that equipment. There’s a near endless array of sensors and things you can get now that work using Z-Wave, ZigBee, and even HomeKit that work DIRECTLY with HA, meaning that they don’t require commands to be sent up to the cloud via the Internet and then come back down to your device.
There’s an easy answer to that…don’t use IoT devices. I recently rebuilt my HA setup into a VM running on Proxmox, added a Zoos USB to ZWave dongle and then replaced every device that needed a network connection with a Z-Wave device. I have nothing left that needs, or can even connect to, the Internet and all of my routines / automations are fully local. I can turn my Router off and the only thing it will impact is remote access and voice control.
I’m reading your comment from world. They were doing upgrades earlier which may be why you couldn’t get in.
Even if the project is verifiably hacked the instant that remake becomes available on the web Disney will sue the shit out of them. It’s just how Disney is.