I can think of three solutions.
Ring Range Extender V1
Ring Range Extender V2
Lowe's Iris Range Extender with this driver:
[release] Iris v1 Range extender zigbee driver
All three devices have batteries in them and can report a power failure even when the outlet they are plugged in to is dead. This is of course all assuming your Hubitat and network are all pugeed in to a UPS.
