Hoarded condemned house

My mother in law is a hoarder. Her house has been hoarded for longer than I’ve known her, but after my father in law passed, things got worse and way out of hand. They lived in separate homes right next to each other (his family built both homes in the 40’s and he didn’t want to lose the home he lived in after his parents passed away so he moved from next door over so both homes could be homesteaded). Well, in December, the sink in her kitchen had the pipes freeze. The home has no insulation in the exterior walls and we live in MN, so it got cold, froze, cracked the pipes and when it thawed, the water just kept going. We believe for 2 days before it started flooding the yard. I called 911, they came and shut the water off and condemned the house. She has a HORRIBLE mice problem on top of the hoard. She and her 2 dogs now live in our basement until we can figure out what to do with them. She’s a senior, she struggles to care for herself and we have a baby so we can’t really focus on her like she would need. She’s letting the basement get like her house was and it’s pissing us off, but my husband doesn’t want to “abandon” his mother. She is wonderful. I love her dearly, but with her memory going and having a hard time with self cares, this isn’t the long term solution.

My question is, we obviously need to sell the home. What is the best way to go about this? An ”AS-IS” buyer? We have to do a cash sale I’m assuming because of its condemned status. The home is absolutely beyond repair. We’ve been trying to help her for years and she wouldn’t allow us to. She feels like everything is being taken from her and I get that, but the house and everything in it has to go. The amount of mold that must be in there is beyond health hazard. How can I help make this process fast and easy for her?