I’m going to arrive at LHR from ARN on Friday at 09:35 AM and will fly to MAD on BA364 at 4:45PM.
The time in between I would like to spend working, which will include conference calls.
I would need a desk and fast internet access.
I have BA Silver status and PriorityPass.

Is there a quiet place to work somewhere? I would also be ok with moving to a different terminal if necessary (have gone to the CX lounge in T3 several times when I was Emerald.)

I have already googled, but all threads I found were several years old, so I was worried they might be outdated.
The Regus business center sounded quite good, even though it’s landside. (I believe I got some Regus vouchers a few years ago, but I don’t remember how...)

Maybe a better option has popped up in the meantime?
Would the Concorde Room be useful? I’m sure I could find someone to guest me in...

Thanks!