Lounge access on overnight layover
So we are looking to switch a JFK - IST Business Class on AA/BA Metal (w/ Aegean Air separately to Athens) for a ATL - ATH flight (AA/BA metal as well), with an overnight layover in LHR. Question is, given our connection is within 24hrs. of arrival, albeit the next morning at 7am, can we still access Business Lounges in T3 upon arrival? It would be nice to be able and grab a quick bite and drink b4 heading out to a Hotel.