I was in this situation nearly 3 years ago.
ds1 was 2 hr birth, 1st contraction 30 mins after waters went.
Ex (then dh) was working in london mon-fri, and while he could have got home in a couple of hours (min) at times, at night it would have taken longer.
I had read various stuff on BBA, but earlier on in pg.
As it happens ex was home when my waters went, 1st contraction 10 mins later, ds2 born within 15 mins after that - at which point ex called 999 (I had called hospital after waters went, and mw called back when I was having 1st contraction).
Afterwards my community mw said that she should have given me a list of what to do in the event of a BBA. But also said that if there were complications then it wouldn't be a BBA - the complications would slow things down. In reality the vast majority of BBA's are very straightford and assuming the baby is breathing then you just wrap it up, sit tight and wait for someone to turn up.
She also said re cord that if it was looped round baby's neck (as my ds1's had been) then in a fast BBA it would just all be birthed and would unravel once out. I think the key here is being fast it has little time to do any damage before the pressure is released - but this is just my thoughts.
I didn't do anything with the baby except cuddle him, 999 asked if he was breathing - he obviously was.
Ambulance turned up about 20/30 mins later, looked at us both from the other side of the room, and said things were obviously ok - they would wait until MW turned up. They didn't touch him iirc.
MW arrived about an hour after the birth, placenta hadn't come out at that stage. She cut the cord and I eventually pushed the placenta out.
Things I read beforehand included ensuring that the house was accessible - ie unlock the front door, I appreciate this may be difficult, so maybe spare key in accessible place or with neighbour?
Carry phone with you at all times, and keep one by the bed at night.
My ds2 was born just before midnight and ds1 slept through it.