Thermostat remote sensor DIY?

Has anyone successfully used a remote temperature sensor in a way similar to the ecobee sensors, but with a different thermostat?

I’ve got a nest, and I like it’s learning capability and from what I read about ecobee the nest is smarter in handling home and away. I like that I just set an awake and a sleep temp/time on nest and it just figures out the rest.

There aren’t any remote temperature sensors on the market for the nest and I’m considering working out my own way of doing it with my zwave temperature sensors, but don’t want to reinvent the wheel if someone has already done this.