@Ieva-and-Maikel0, I fear there is not much you can do. I had such effects of the minimum sta6 limits too , it’s counter intuitive that the limit is not on the period for the whole stay, but the limit concerns the start of a stay.
what you should do however, is learning a lot about your guests. 3 nights for several people in a whole apartment over New Year is about the worst setting. So make sure, that you know who comes, when they arrive, checkout, names of the guests, what they plan to do, no party at the property, no extra guests, checkin with inventory and checkout as well, pictures will be taken at checkin and out.
If the answers are satisfying, go with it. If they are not, call airbnb to try to get a cancellation for feeling uncomfortable with the guest.
And if you annoy them enough in the process, that they realise it’s no party venue, you can always offer full refund.
Ah and mention your aunt sleeps on the next floor.