I work for BA WW (Worldwide) and used to commute from both France and Italy until some years ago.
We have two different standby duties at BA WW, either QRS (Quick Response Standby) or 2 hour standby. I was lucky most of the time to be rostered QRS during which BA provides you with a hotel room. Whenever I had 2 hour standby I would most of the time stay at a nearby B&B to LHR.
Most commuters from abroad either have a room somewhere close to their base or either stay at a B&B or with friends.