I managed to finish off the last pace run before the half marathon this morning, completing the 6K route in 27:52 (avg 4:39min/km pace). That was a little faster than I was trying to do, but it's difficult to nail pace precisely with such a short run as any little error can become quite significant. Either way, my pace was relatively stable and stayed within a reasonable envelope so I think that I'll be okay for race day. My heart rate averaged about 164bpm (74% HRR), peaking at about 174bpm (80% HRR) near the end both of which were quite comfortable.
After getting back and eating lunch, I headed back out on the bike to put in one final session before the race. In order to reduce the load, I elected to do my normal cycling route in reverse so that the steep portions (600m @ ~5%) were downhill and the long incline was uphill (3K @ ~3%). This actually worked a lot better, as my legs were a less tired by the end of the ride and my average heart rate was actually higher than normal (as I could push more evenly throughout the ride, rather than pushing very hard up the hill and then coasting a bit to recover).
With only an easy 3K run on Saturday morning left, this is pretty much the end of my proper training, so all that is left now is to let my body rest over the next few days and prepare itself for the race itself. The last few months have seen me dramatically increase my mileage, and I've run longer and harder than I've ever done before. As such, I'm confident that I've done everything possible to prepare for this race so it's just a matter of getting ready for Sunday to reap the benefits of all of that work.