I reach 200'+ with a zigbee extended range router.
I'm not an arduino user, but HubDuino comes to mind for the voltage reading
https://community.hubitat.com/t/release-hubduino-v1-1-9-hubitat-to-arduino-esp8266-esp32-thingshield-integration-st-anything/
Also, I found this
http://www.zigboat.com/product/battery-sensor/
