For long survey, it's not always easy to fill the survey in one time using Survey123 Web version (or to allow multiple users filling in the same survey record submission). It will be nice to be able to have a workflow like this:
1. Start a new record submission
2. Fill some questions & Save the submission
3. Send an email to the recipient with an URL allowing him to come back to the submission (e.g.: survey123.com/{SubID}
4. Complete the submission