The real problem, of course, is motivating myself to get up so early on a cold, dark February morning. If only there were cafes open at that time, it would be so much easier! Keep going till the next cup of tea and slice of cake or beans on toast!
I enjoy riding to the start of events when I can, even though this sometimes means setting off at about 3am. It sounds like a rough deal, but starting from home at 3am is much better than starting an event at that time (as some 300s do), because you don't have to factor in travel time to get to the start.
Also, riding to the start is much easier from a morale point of view than being faced with having to ride extra distance at the end of a calendar event. I rarely feel like riding home after an event, whatever distance, and usually get the train.
On the other hand, if you add the distance to the end of the calendar event rather than before, you don't have the guesswork element of how much time to allow.
I don't do ECE anyway - my sole reason for riding to the start is simply that I prefer not to drive if I can help it.