Ryan/Dusty checked in at 12:55pm and Lulu/Lala checked in at 3pm. (Thanks Phil!) Production must have forced teams onto the same overnight train to Glasgow (leaving around midnight, with plenty of other trains before that), or held them up for an overnight stay somewhere.
Anyone else thought the check-ins were weird? We never see shots of Phil announcing the teams' placement, just a disembodied "You are team number one!" voiceover with footage of the bus exterior.