I am considering flights on British Airways from one place to another in Europe, via London Heathrow (LHR). One itinerary has a 11-hour connection, from 21:00h the night before to 08:00h the next morning. The other itinerary has a 23-hour connection, from 09:00h the morning before to 08:00h the next morning. For very long, overnight connections like this, will British Airways be willing to check my luggage through, so that I don't need to see it during the layover? Or is there some policy that for overnight layovers, they always require the traveller to pick up and then re-check their luggage?
Yes, I can pack so that all my overnight things are in carry-on baggage, so that I don't need access to my checked bags. Yes, I am aware that baggage storage exists at LHR, but not seeing the baggage at all is even easier than schlepping to and paying for storage.
A related question, Long layover in Heathrow - with checked baggage, generated the answer, "Assuming that your 10-hour layover is not overnight… you can generally expect to have your baggage checked through such that you won't see it at all in Heathrow." But in my case, the layover is indeed overnight.
Update: described the endpoints of my journey less specifically, so that people won't get hung up on the advisability of going via London, and can focus on the topic of the question: BA's baggage check policies.