No need to sweat or panic. I went through the same procedure few months back. But when I renewed my license I had my OPT card with me, while my I-20 had already expired. So my suggestion to you, give it a shot with your current I-20 (even though its expiring soon) and explain them your work permit on the approval phase. If it doesn't work, wait for your OPT card and when you do get it, take your OPT card with expired or not expired I-20 (doesn't really matter) and your couple local address verification proof and you are good to go. FYI, even though I had one year OPT, my renewed license has 5 year expiration date.