need subsitute season

I am planning on making a ranch pasta salad, which I found in the forum. My problem is that it calls for onion powder. There is no way for my to get this in the next couple day (due to an accident, am unable to get out and about on my own). I am also low on a lot of seasoning, the one I do have is garlic powder. Would this be ok to subsitute, or is there another way to get around this?