Most of the warnings at LHR atm seem to be for flight departing in the evenings, Im really hoping the mornings are less hectic for departures. I have an 8:30am flight on BA and even though Im staying in a hotel at the terminal, I plan to be there when checkin opens at 5am (for J).
If flying Y without status, you can only check in 3 hours before I believe.
However Overnight Bag Drop is available if you are travelling on a flight departing before 13:00, you can check in your bags between 18:00 – 21:00 the day before.