I have a Smart thermostat that periodically goes off-line. I have been told by the tech-support of Lennox that the XFINITY router has its settings changed periodically and that it can be done centrally without me being able to control it. I would like to add a second router to connect to my smart thermostat. It would have a separate SSN and I would like to be able to set it up so that the thermostat is the only device on the network. Is this possible? What would I need to do to make this happen? All my other devices would stay on the Xfinity Wi-Fi networks.