You sound like you do enough to get around just fine! 16k is exactly 10 miles so you're getting on for the right distance in training. Try and simulate a half-marathon at some point before you go and make sure you're happy with your pace.
I don't think you need to step down your training just yet, still about 4 weeks to go! How long are you used to running continually for? I guess it would make sense to try and make sure you're comfortable running for say an hour and a half continually.
I was due to run a half marathon in March and ended up missing out through illness - was so miffed! 10-miler is as close as I've competed at... I'm doing the same this October but running to a specific strategy... might not be worth me getting in to that because, although the distances are
similar, there's still over 3 miles' difference
