Matt,
What I usually do is a reverse taper. I take the week off - easy runs or walks. Depending on how your body feels then resume training.
Example
Week 15 - 7 miles
Week 16 - 5 miles
Week 17 - OKC Memorial Half
Week 18 - 5 miles
Week 19 - 7 miles
Week 20 resume to the regular schedule adjusted to your next race day.
Everybody recovers differently so best to listen to your body.