You can always still renew but since your IDR plan wasn't renewed on time your interest will capitalize (no biggie if your goal is forgiveness). Additionally, your loans will revert to standard repayment, so if you don't turn it in right away, ask the rep for a deferment. If you do turn it in ASAP, doesn't matter because there should be an administrative forbearance applied when they get it. Since it's when it is, I highly recommend the online application that links to the IRS. You can always renew for a cheaper payment at any time if it doesn't bring you to $0/ month.
Oh and for the record...yes, they're our financial responsibility and we should remember, the Servicers are supposed to send us a reminder at least 1 month on advance. I put mine in my calendar on my phone because they rarely do it. You're not alone.
Another thing is that if you switch IDR plans you need to make this special payment in between. I'd also set a reminder in my phone; the administrative forbearance times out in 30 days. They've sometimes been taking longer than this to process applications.
Hope this helps.