Extending trading time longer than 6 days

If the seller can not confirm the trade inside the 6 days, because the SEPA transfer did not arrive in time, what will happen?
What if the money arrives after 8 days? Will the trade still work or does the system cancel the trade?

The system does not cancel the trade. From my experience, there’s no reason for a SEPA to take that long, though.
After 6 days, the button to open mediation becomes visible.
After 20 days, the trade can be sent manually by one of the traders to arbitration.