@Mindy37 I can only speak about my personal experiences...
I’ve had six(?) guests stay under the same circumstances, five were lovely, one was ok, nice enough, but left early and argued about refunds and one of those mismatched ratings where you get 5* for every category and a 3* overall 😒. The last was hellish - not intentionally horrible, but incredibly anti-social.
In all but the last case they’ve either extended their stay, having asked permission first, and it was gladly given, or they have left early because they found somewhere but largely, there was no refund required.
I personally relocated for work a few years ago and had to find a rental place in a 36h visit to a strange city. It was stressful, difficult, and we only found somewhere as good as we did cos we lucked out. I’d hate for someone else to be in that position - moving home and jobs is stressful enough by itself, and we didn’t even have kids to worry about!
If you’re worried, you could limit the booking to 27 days (or whatever is the cut off for permanent tenancy) and block the calendar after. After three weeks you could reassess and make a decision about extending them or putting the space back up to someone else. You could make sure they have ID verified to reduce any damage concerns. Plus you could ask for a security deposit.