@RWB, I can confirm that a rising edge on WKP will wake the P1 from deep sleep. I can also confirm that the WKP pin can wake a P1 from regular sleep (I only test rising edge). 
@peekay123 Sweet! Thank you for taking the time to test this.
I can confirm that the low energy harvesting chip with a single solar panel like I sent you has kept the Photon up and running for month now posting temp and humidity data every 5 mins. It’s sitting in a window which faces noon sun. It’s connected to a 5Ah LiPo battery. Not sure if you had a chance to test what you have or not.