By Default page will redirect after 5 second,
5 second setting are coming from logout.phtml file.
Just change value at below line
$($.mage.redirect("<?php /* @escapeNotVerified */ echo $block->getUrl() ?>", "assign", 5000));
To,
$($.mage.redirect("<?php /* @escapeNotVerified */ echo $block->getUrl() ?>", "assign", 36000));
Now page will redirect after 10 Hour.
You can change value according your need and after your work is completed you can set 5000 in above file.
Core file is,
vendor/magento/module-customer/view/frontend/templates/logout.phtml