said by bburley:link was still running ... unable to return pings properly or pass data. It could have been the oscillator/clock
If you are sure that your IP network was fine, then it could have been the main oscillator (randomly) going out of spec and affecting multiple clocks on the PCB.
said by bburley: but then why should I expect that lowering the power level would help in that situation?
As temperature goes down, power amplifier draws more current and becomes a bit more non-linear ... which causes a bit more bit errors. If you lower the PA dBm level, the situation always improves as long as the link margin is good.