Questions regarding Apple Watch for an elderly person.

Hello,

I am considering to buy an Apple Watch (4/5/6) (not the LTE version) for my father, so he can call me, and also have the SOS and fall detection features.

What is not clear to me is if those features will work if his iPhone isn't in the same room. E.g. If he goes to the bathroom, which will have WiFi but probably too far for Bluetooth connection with the iPhone, will he be able to use those features?

So the iPhone will be in one room, it will be turned on, and will have both WiFi and Cellular connectivity. The Watch will be in another room, connected to the same WiFi network.

In my country eSim and "Wi-Fi Calling" are not supported. So I don't want the calls to be made directly by the Watch, but by utilizing the iPhone in the other room. Is this possible?

Thanks