You can't have two hubs, [ETA: connected to the same device - you can have two hubs running in parallel, but that does not seem to solve for your issue] so that solution is out. However, it seems you can make this work by connecting your T-stat to Hubitat via an integration, then using the Zwave sensors, connected to Hubitat, to direct the t-stat.
Take a look at these threads:
and definitely this one, reading to the end:
