Hmm maybe, I cant test how much current you can put on it before it dropping atm, but heres a 100mA test.
That shows 0.05hours before dropping, with the photon drawing 80mA when running for a few seconds and <100uA during sleep that could be several hours running with a vin slightly over max, it will likely still work and not take damage since the voltage regulator has 6.5V absolute max though…