Well you'll be out of the water 10 minutes faster than me but the bikes a big unknown as I'm not really a cyclist and at this point have never been over 56 miles (gulp!) however I've got two 200k audaxes in April and May so that should be revealing. Pencilling in 5.30 for the marathon but who knows.
Had some fun at lunchtime looking through the times from last year. I started at the back where I expected to find more kindred spirits. Page after page of DNFs and DNSs, some with excellent times before the marathon, one 50m swim and 5hr bike but still DNF. One finisher with a 7hr bike and 7hr run, sounds much more like me . One poor sod had a nearly 9hr marathon. Ouch!