Originally Posted by
kebosabi
Instead, I'd opt for getting into LGW directly by way of the Caribbean or Mexico (or from MCO as soon as the ban is lifted on taking BA flights between the US and UK), staying put there without the need to enter the UK and collect baggage, and smoothly transfer to the connecting flight without all the hustle and bustle.
The OP's best case routing of LAX-LHR/LGW-MLE would arrive at LHR around ~2pm and depart LGW at ~7pm. Plenty of time if everything's on time. If you wanted to pad it a little you could take a connection on the way over in DFW/ORD/JFK etc. and arrive in LHR around late morning to midday.
On the way back, MLE-LGW arrives around 6pm, too late to catch anything on AA ex-LHR back to the states, so you'd have to overnight in London regardless.
Most of the BA Caribbean->LGW flights arrive in the early am, which considering the 7pm LGW-MLE departure would mean a 10+ hr. layover in LGW. Ick.