Regarding finding your way to the runway, we had low-vis pages in the aerodrome booklet for LHR showing the magnetic direction and distance of each section of the route to the runway. The distance was set on the Ground Run Monitor at, say, the start point at the end of the Bravo cul-de-sac.
The GRM would be reset at the threshold to the TOR, so you'd know how much runway you had remaining in the event of a rejected take-off.
This was used as a crew 'check' on the Ground Controller's instructions using their Ground Movement Radar (was it called 'ASDIR'?). Not that we didn't trust them, you understand.
I never heard of a crew unable to taxi out, even in 3B. The combo of ATC radar and the GRM/chart usage worked like a dream.