The night leg that I witnessed (Leg 1) ended in Michael & Moe being eliminated. During the leg, I overheard a crew member at the graffiti detour (we see Kim & Penn performing it in the promo) say that there was a darts task tomorrow. I returned to the Natural History Museum the following day to see if teams had continued on but could find no trace of them. I'm now wondering if they did some interviews with teams that same evening and then set them off again for a second leg after a 'no-rest pitstop'.
About 36 hours after the end of Leg 1, I found the teams again with some canny sleuthing at a hotel in Kensington. If the second leg was completed by this point, no team had been eliminated in leg 2 as I saw all 10 remaining teams board the train from London Euston to Glasgow Central. I followed the charter bus that took them from hotel to station, and saw them all board. I also heard the teams discussing 'the roadblock' and if they had struggled. At the time, I couldn't understand as I hadn't seen a roadblock, only some active route info and a detour, but now I believe the darts task is a roadblock (we see Ryan, Arun and one of the twins completing). I think the cake task is an ARI, but could also be one half of a second leg detour. I think Phil gives teams their clues to start leg 2 on the double decker bus, or teams have to search for him on a nearby double decker from the pitstart...
So either the second leg is mostly in London, and then teams are bunched up via train to Glasgow, and set off for a final task in Luss before a pitstop at the University of Glasgow cloisters (we see 10 teams racing from the train in promo footage). Or the second leg is a non-elimination given all 10 get to Glasgow...
Hope that makes sense. Given we returned with 8 teams this year (apparently) for Leg 4, it seemed likely that all 3 legs in UK were elimination, so I lean towards the idea that the second leg sees them do a few tasks in London during the day, before training to Glasgow to finish off the second leg with the 'pop the bung' task in Luss, and travel back to Glasgow for Orain Mor route info (might be edited out) and Cloisters pitstop. All speculation...
And then a third leg in and around Glasgow city ending in elimination for January 12. Leaves us with 8 teams for the re-start (with a few eliminated teams returning to fill the space of those that could not return). Thoughts?