I had a pretty good day all in all. I think I did 212 stations total.
I planned forward to a bail-out station near my hotel, and backwards from the last train that went to my intended finish station; these two bits were 40 minutes adrift!
I went to most of the west half of the map first including Chesham and Heathrow, and everything was bang on plan. Then I had a lovely Loop and an epic Epping and somehow had found 30 minutes of the 40 on reaching the Overground link towards Walthamstow Central, and at this point I thought I might just make it.
Then I got to Finchley Central and just missed the Mill Hill East train. 11 minutes to the next one
. Went up to HIgh Barnet where I just missed the 307
and I (sort of) quit at that point.
I went back to my hotel, but it was so dismal there that I went out for part 2! Did all the fiddly stuff around and just north of Stockwell, then down to Morden, across to Wimbledon and back up to Zone 1 for a few more stations, finishing at Barbican at about 10:45.