>>It's the stuff that they can't do that is driving me around the bend.<<

There are people who specialize in helping with that part, some volunteer, some professional. Ask at funeral parlors or hospices to find them.

>> I've pretty much given up until I get death certificates. I'm pretty much screwed until I get those.<<

Sensible.

>> I'll have to do the house myself. She was pretty much a hoarder, though a very neat one. Everything was behind doors. At least the local charities are going to benefit as will the food bank.<<

At least try to get someone to sit with your for that part. You may have to make decisions, but someone else could carry things, box them, call places to say their pile is ready, bring you snacks and tissues, etc. It's not a good job to do alone, just for emotional reasons.