Google Nest Community

I am curious if a nest thermostat (any version) with a ‘C wire adapter’ will work with my existing heating system. I have no wires from my furnace (basement) to my thermostat(upstairs).Will the nest thermostat communicate directly to the c wire adapt...

Thinking of buying a Nest thermostat with the C wire adapter.1. I have no wires running to my old thermostat upstairs (air handler in basement). Will these 2 products (thermostat & adapter) solve my issue? 2. Any idea how long the batteries will last...