If you MANUALLY change the date/ time in your kobo reader, you can read it as long as it takes you, just keep the date somewhere in between the date borrowed and the date expired. If you do this, you can keep reading, even after you get the Adobe oops error message.
or keep the book open, as ottdmk suggests.
The book will not be deleted or forever blocked after synching, either, like Amazon. but you may have to change the date again after syncing.
and don't add another library book until you've deleted the one you had to extend the time on AND reset the time back to real time. ...otherwise the new book won't be able to be opened. ....using real or fake time