I have same issue. According to this you have til the 20th to send the 4868 in by mail and if you owe, you can pay at IRS Direct Pay. Don't know if there's any penalty or interest associated with paying 24 hours late. https://ttlc.intuit.com/questions/4742863-what-can-i-do-if-i-filed-my-federal-new-york-or-massachuse...
