Lots of chip seal around here, but from my experience when I'm close to the bars the tires wear mighty fast. Running your tread to the limits on a thousand miler is not advisable, especially with travel loads and potential rain.
This!

The fastest wear on all these (bike) tires is the last 500-1000 miles. Faster if you are putting in long distance travel days.
I just replaced my front Metz with another a few days ago (not to the bars). It had maybe 4-600 OK miles left, and then a few hundred more not OK miles before it was completely shot.
I've slipped badly on hot (nearly shot) tires and pavement and it sucks. Rain would be worse.
What I started doing is always having a new front on hand. With two bikes, it's never going to get old (by mfgrs date) sitting in my shed. Then when most of the tread is gone on either bike, it gets replaced (no waiting for delivery). Which reminds me; it's time to order another. (I always run Metz, and 8-9K good miles is all I ever get. I went to 11K once... never again.)
Keeping a log on all bike maintenance, including tire change mileage and dates, I go by miles as well as how the tire looks. Every time I hit 8K on my ME880s, it's about time for a new tire.
I've tried a couple abnormal front tires (bias rear on front reversed, smaller steel belt front) and not been happy enough with the results to do that anymore.