For what it's worth......
From an engineers perspective - it CAN happen.
I was once in an off line airport with a 747 classic. We put the aircraft to bed at night and next morning after the aircraft was powered up, fuelled, loaded and tech crew tried to use the radios - both system 1 and 2 VHF were inop. Swapped 3 into 1 with success but MEL states you can only have SYS 3 inop (which is for data). Co-incidentally our CMU (Communications Management Unit was also inop and under MEL which had already rendered our SATCOM and ACARS inop) We had to wait 24 hours for two spare VHF transceivers to be flown in.
Whilst number 3 VHF can be switched from data to voice to give you one voice option, if two out of three can go belly up without warning during an overnight sleep, I guess it's not unfeasable to lose all 3 VHF's. This of course occurred before flight and i've only posted as an info item. I'll leave the piloting/inflight decisions up to you guys.
