To the OP - do you have any status with Hilton?

I have had success at a UK Hampton in getting an inflexible points+cash stay "held" as a credit for a future stay. This was owing to a bereavement - and I had booked into a different Hilton property in the NorthEast to attend the funeral. I'm HH Gold and had stayed with both properties in question multiple times so there was quite a bit of goodwill.

However, to simply ask Hilton to refund you in full and foot the loss for something that was neither your nor their fault is probably not realistic. The non-refundable rates are cheaper for a reason I'm afraid.