How can I file an additional extension if I’m traveling overseas?

[NCperson]

@Hannab4 see link; I don't see that any further extensions are possible unless you fall into one of the 3 bullets listed in this link.

https://www.taxpayeradvocate.irs.gov/news/tas-tax-tip-important-reminders-for-october-extension-file...

if you are due a refund, you have until Oct 15, 2026 to claim the refund.  That is the deadline I'd worry about. 

if you owe, then interest and penalties have been accuring since April 15 - best to make an estimated payment immediately to stop the interest clock. 

[xmasbaby0]

And...understand that online tax preparation and e-filing will close down after the October deadline.   If you do not finish preparing your return by then, you will need to use downloaded software on a full PC or Mac, and your tax return will have to be filed by mail.