If you have glass insurance, just throw a brick through it, and have them replace it or try and make the initial crack longer/larger so it goes at least 6 inches on the wiper path.

I guess if that's not an option, just get the new window before your trip and get the glass coverage added anyways onto your plan. I've checked (and my insurance rates are pretty high around $1600/6months) but it’s only an extra $20/year for the glass coverage over here in NY. Even if you go 5 years without a replacement, that’s still way cheaper that paying out of pocket for a new windshield. A buddy of mine actually had his insurance canceled after 3 windshields in his jeep were claimed. The first was a turkey flying through the window. The second cracked on the way home from the glass repair place, and the third cracked about 3 months later in the winter taking ice off the window with a scraper.

I was surprised when my window cracked from a rock, well not really surprised just startled I think I was going near 85 passing a large dumptruck on a back country road, I couldn't remember if I had glass coverage, but after a phone call it was already on my plan and they let me call any glass shop of my choosing for the replacement.