Originally Posted by GeezerCouple

I hadn't realized that it was the return flight, which does change things. (However, given the advance notice, I'm a bit surprised that the insurer isn't asking or expecting you to try to mitigate their loss, by trying to get another flight the original day.)

Will you have any receipts for the extra night, such as hotel and food? Or are you staying with friends?
Look at your policy. I'm not sure that clothing would be reimbursible if you aren't dealing with lost luggage. Perhaps you could claim <joke alert> that your shoes wore out JUST AS you were about to leave, so you needed a new pair for that last day
It probably depends how the policy is written.

GC