End survey based on time limit

Hi,
Most of the questions in my survey display a timer so the participants can see how much time they have left to complete the current page (e.g., 5 minutes in total). I would like to send them to the end of the experiment if the count down reaches 0 (i.e., if page submit >300). The only way I found to do this is via surveyflow + branch...however this requires having each question as a block (which is extremely difficult at this stage). I was wondering if anyone knows how to do this with JS.
Thanks a lot in advance!
Anabela