I would ring a funeral director and ask the question you’ve just asked here, about advice. They are very sensitive and will be as helpful as they can.
Personally, I would have the funeral now as I would feel a bit in limbo having to wait an unknown length of time, and allow the retained parts to be disposed of by the authorities in due course.
But that’s just my personal view.
I’m so very sorry for this situation you are in bednobs, and the overwhelming sadness you’re feeling, I wish I could offer words of comfort but I don’t think anything I say would make a difference. You’re in my thoughts x