I concur with the advise above
1. Virtually zero chance BA will through check your bags. Pigs might fly before your bags are checked through.
2. The timings are too tight to risk the unprotected connection and checking bags back in
3. Your best (free) bet is that if you're on a non-redemption WT Plus or CE ticket is that you have the chance to change you flight for free on the day. You can do this online shortly after midnight. If it's a redemption ticket cancel for £35 per ticket and rebook. But this is subject to availability on the other flights on that day.
4. Or pay to change/cancel your BA ticket. Be aware that to change a ticket BA will send your request into a reticketing queue that is outsourced and typically takes weeks. Cancellation and rebooking yourself by buying new tickets is likely to be less stressful if you can wait for the refund.
5. Best approach to mitigate risk for Ex-EU if you can is to travel the day before and overnight at or near the airport.