is it going the way of EK? What sort of locations do BA longhaul folks commute from (i.e., can you pretty much live wherever you want in the country)?
You'll have to ask the EK folks about EK...
As for BA - commuting from within the UK shouldn't be too much of a problem, for the foreseeable future, as long you're not too far off the beaten track. That said to be honest it's not a easy as it was even a couple of years ago to produce a commuter friendly roster with decent gaps between trips but even so you can live pretty much anywhere in Europe that's near a handy airport, and there are a few who commute from even further afield. Whether that will continue to be the case as BA Long haul moves closer to full EASA FTLs in a few months (where for example "back to backs" almost certainly won't be an option), and then again in a year or two when there is another step change in the scheduling system formerly known as Bidline - who knows?