Had to pull in a final cycle on my last available day in May to get the numbers, but I actually completed the challenge. I did find it quite a struggle to get all the distances in over the course of the month, never mind the thoughts of doing it in a single day. So here are the totals (excuse the formatting).
Distance Time Average Pace Percentage Estimate Time Time Remaining
Swimming 3.90 3.00 46.14 101.04% 2.97 -0.03
Cycling 198.75 7.66 2.31 110.27% 6.95 -0.71
Running 48.75 5.33 6.56 115.63% 4.61 -0.72
My main aim for July is to knock some time of the above. I'm almost half way there now, but while my swim and run times are (much) better, my bike times are actually slower and given it's such a big part of the total distance, it looks like I might actually be slower! That said, I'm probably going to do a 50km fast-ish cycle tomorrow with a friend, so that should improve the stats.