Yes
- Buy a €99 Home Assistant Green
or (more effort & more power, less (or more) silver coins)
- Install VirtualBox/VMware/Hyper-V/KVM on a (old) pc / laptop, or a thin client like Intel NUC or HP Elite;
1a. Download, unzip and just start a HA virtual machine image:
1aA. For Windows OS:
https://www.home-assistant.io/installation/windows/
1aB. For linux OS:
https://www.home-assistant.io/installation/linux
Or a €0 way, as added by @RonnyW :
- When you own a NAS with Docker support, you can run HA as docker container
Next
- Buy a supported zwave stick, like, a €60 Aeotec Gen5+
***
- Plug the zwave dongle in a USB port. If you use a virtual HA machine, make sure the ‘real’ USB port is forwarded to the VM
- Install the HA zwavejsui addon
https://www.home-assistant.io/integrations/zwave_js/ - Pair all Honeywell T6 to HA using zwavejsui
Homey
- Install Home Assistant Community app
- Add the T6 devices as Thermostat via the HA Comm. app.
***
) for EU use: why no Gen 7?
Aeotec Z-Stick 7 USB stick (ZWA010): the EU version is not recommended due to RF performance issues