Thanks for the replies.

The problem I have is that I am more than a bit OCD about having plenty of time in the event of disruption, plus I like a non-stressful start to a trip. Normally I go home first and pick up the Piccadilly line directly from home if it’s later afernoon, but I won’t have time for that.

My question is more around the connection between tube and HEx, and which is the most convenient connection. I’m pretty comfortable with walking from Lancaster Gate for example, not least because I know my way. I have recollections in the past of there being some interesting interchanges, not least because the Circle line isn’t a Circle line any longer (I take the Circle line every day for my commute, but I’m in the continuous south side of the route.)