Can anyone recommend a 2-wire thermostat (batteries for power are ok!)

[Sasquatch]

Can anyone recommend a 2-wire thermostat? I have a number of Insteon 2441TH thermostats which are great, but in one location, one of the 3 wires is damaged inside the run somewhere so I only have two wires- the 2441TH requires a common power line which I cannot supply. I just need a simple on/off on that line - currently I'm using an old fashioned mechanical thermostat which works fine, but I can't control it with the ISY. Sounds like Z-wave will work?