My condolences on your loss.

When my mother died two days before an ex-FRA trans-Atlantic itinerary last year, I called BA (ticketing airline) to cancel and they offered a total refund for me and my other half, paid once I'd emailed the death certificate to them.

In fact all the travel companies involved including Hilton and Priceline* gave full refunds, which meant I never had to claim on the travel insurance. When I did call Amex Platinum they told me that the medical exclusions which I had thought just applied to the traveller(s) also applied to the deceased family member whose death was causing the cancellation - this meant such a claim would likely have been denied, so not having to make the claim and argue it through thanks to the unpublished flexibility of the travel companies was quite a relief at the time.

*This was for a Priceline 'Name Your Own Price' hotel booking which is notoriously locked-down as a no-refunds/changes/cancellations booking, but they said they would contact the hotel in question to explain the circumstances and ask on my behalf. Thankfully they agreed to a refund.