I'm pretty sure Alexa doesn't have the concept of a device that is both temperature sensor and motion sensor...so if you want both, it's going to have to be two devices somewhere/somehow. With the Hubitat Alexa skill that's going to mean virtual devices.
I feel your pain though, I had a similar problem the other day with a plug-in dimmer that happens to have a temperature sensor would show up in Alexa as a temperature and couldn't even be used to control the light. 
I wish for devices where the driver is presenting multiple capabilities, we could choose which ones are exposed to Alexa.
