I wonder how they will pick which homes to heat or generally how to share that with general infrastructure. Also wonder how much will go to Switzerland (which has much denser housing in that part) and how much to France.

I live not far, work in Geneva and have few colleagues living in/next to that circle. For sure they would appreciate using such source of heat if its frictionless integration.

Mostly likely they'll supply heat to an existing district heating network.

They released a map [0] of their heating network. Maybe you can find your house on it?

[0]: https://images.fineartamerica.com/images/artworkimages/mediu...