Overnight at LHR

I frequently overnight at LHR to connect with VS flights but I am always on a separate ticket and PNR so have to collect and re-check my bags the following day. That is not a problem. However I have booked a through ticket on BA which will entail an overnight stay in LHR for an early morning onward flight.
I am well aware that Aer Lingus will check passengers through on BA flights and issue boarding cards for same day flights but I wonder if anyone knows if this will happen for my flight or will I have to collect and re-check my bags the next day at LHR?
I am well aware that Aer Lingus will check passengers through on BA flights and issue boarding cards for same day flights but I wonder if anyone knows if this will happen for my flight or will I have to collect and re-check my bags the next day at LHR?