I'd change it, but there's no reason you can't wait for those two days till you get back to Iowa. Depending on the bow weight there probably isn't a whole lot of danger of the string just snapping, but I wouldn't shoot it anyway. There's no purpose in blowing the bow apart for no reason.

With two strands broken I'd say that eventually the string is going to creep. The draw length will get longer,. The weight will go up. The nocking point will move and the bow will jsut plain go out of tune. That's a best case scenerio.