Would a PG9905 with remote temp probe meet my need? or would it only trigger on set thresholds?
This would be the way to do it. PG9905 reports the current temperature to the panel in addition to alarms at thresholds. Up to two PG9905 sensors can report temperature in Alarm.com for you. You can mount the PG9905 inside and run a probe outside.
Could anyone point me to a resource for more info on powerG sensors?
Do ALL of the powerG sensors show ambient temp
No, it is a model specific capability. The PG9914 has a temp sensor, but it cannot be used outside
My thought is that even if the sensor isn’t outdoor rated, I could nestle it under the soffit somewhere out of the direct elements and sunlight. But maybe that’s a bad idea.
I would not recommend putting the sensors there. It is still exposed to humidity, temperature, etc. Only use outside rated sensors outside.