How quickly do they cancel duplicate bookings - is it every night or ?? I'm asking because we really want to be on a nonstop flight tomorrow but there's only one seat. I want to also book the connecting flight so that we are both confirmed on it. I'm hoping to check every hour or so in case a seat pops up on the nonstop, at which point I'll cancel the connecting flights. Worse case scenario is that they cancel both our bookings in between my hourly checks and I can't get us on the same flight to our destination at all!

Edited to add: Refreshed after about 15 minutes and was able to add the companion to the nonstop flight, so my question is moot!