The OP should not get confused between ash and strike.
With the volcanic ash issue, all flights could not fly and pax were delayed for a long time as no one was clear when flights could resume. The was the chaotic.
A BA strike is very different. BA made good advanced plans to fly long-haul flights with regular and volunteer crew, chartered planes for replacement flights and place pax on other One World airlines. Only short haul flights from LHR were cancelled. However, most pax did fly and it was relatively straight forwards to rearrange flights in advance of the strike (as a one week advance notice is required).
So no real need to be too worried about the travel itself. You have have to put up with no hot food on board the flight (and a reduced bar service if travelling in First and Club World)