Hi, no it will be in December.
I do know the area around LHR a little - I can happily stroll between T1, T2, the Queens Building and the bus station etc. (I'm not LHR based but do nightstop there a few times a year). I think I know roughly where T3 is but I would probably go underground if I was going landside.
Thanks for all the advice - I hope to avoid any back and forth trips but it is nice to know what to expect!