When I used the Northern Line from Euston around 1.30pm, headway was 7-8 minutes on both branches. It was quiet down there and very quiet in Euston ticket hall, the latter probably helped by the Avanti on-train announcements that it was closed. A unexpected bonus for me on the way to Heathrow, though.
The Elizabeth Line was about as busy as a normal day.
The Elizabeth Line was about as busy as a normal day.