Narcisistic Mom (88) refuses to move out of motel after what was supposed to be a brief stay. Any advice?

Hello to all, particularly adult children of narcissists. I've been lurking for several months and finally feel safe enough to ask my question. Apologies in advance for what will be a long post.

Background: Mother, 88, is and always has been an epic narcissist, paranoid and OCD. I am 51, an only child, and have one son.

Mother's house is on a riverbank and over the years the river has been increasingly flood-prone, causing her to have to leave the house for a few days or weeks until the water recedes. In December 2013 the flood was so bad that all the nearby homes were heavily damaged. Mother went to the local chain motel, received about $70,000 for her claim, and hired a contractor she knows well to do the work.

It is now July, and she is still in that motel. The insurance is not paying her motel bill--she is. The work on her house drags on, and I suspect the contractor is milking the situation. A couple of weeks after the flood, I asked her when she thought she'd be able to move back home. "Oh, by the end of this week," she said. Every time I ask her, her answer is always the same. The motel managers are very nice, but whenever they see me they ask me how much longer she is going to stay. I learned that motels' liability is different for "guests," who stay a short period, and "tenants," who stay a month or more. I'm sure they are thinking about that liability (what if she falls?), but they feel sorry for her and let her stay.

Compounding the problem: I came here from out of state 5 years ago to be near her and moved into another house she owns that's also on her property. 2 years later, I met a wonderful man and we got married. Knowing that Mother doesn't do transitions well (and neither does my autistic son), my husband and I decided to keep living in our separate houses for a while to help everybody ease into the change. One night, my husband and son got into a row when my son dropped the "F" bomb, and my husband backhanded him. I immediately called my son's father and told him what happened, and he and my husband, son, and I all talked, apologized to each other, and agreed there would be no more cursing or backhanding. Since then we 4 have been happy with how we resolved the situation.

Mother, however, went ballistic. She went all over town telling anybody who would listen that she knew all along my marriage was a mistake and that I should get a divorce. At this, I decided it was time to go. My son and I moved in with my husband, whose house is about 35 miles from Mother's, and I began keeping a "caring distance" from her. All four of us even met with Mother and her pastor, but Mother wouldn't budge. She met with me and my husband, held our hands as if in prayer, and begged us to continue living apart. We told her that we had already lived apart more than a year and that it was time to blend our families. We knew it was useless to bring up her gossip, as she would have denied it. She continued to insist that I move back, and my husband and I decided to let things gently slide, hoping she would give up on us and rent the house to someone else.

In April, I offered to move her things into my former house so she could continue to live on her own property while the work on her house was being done, but she refused. Instead, she suddenly rented out the house, but continued to stay in the motel. Her house is still not ready. She's afraid that mold under the house will affect her COPD (her only health problem--she takes no meds besides her inhaler and O2). She said the estimate from the mold company was too expensive, so she wants to have one of the neighbors "bomb" the house for mold. The contractor continues to drag his feet.

I also suspect she's afraid to go back home because her neighbor who used to clean her house abandoned her own flood-damaged house and moved away. She won't hear of the idea of living anywhere else despite the growing dangers. I suggested looking into raising up the house a few feet, but that requires many permits and a long process from the county, plus a huge expense which she now can't afford due to bleeding her money away on the motel and contractor. Naturally, her take on the situation is, "Well, I'd be more comfortable going back home if you'd live in the house again." Do narcissists take classes in how to be manipulative?!

I really believe her judgment is impaired. I want to protect her, but I don't want to incur her wrath or feed her narcissism. Should I try to do something legal to get her out of the motel? Should I call someone to check the contractor and determine if he's ripping her off? Should I grit my teeth and do nothing, as I have been, because every time I try to talk about it she either waves me away or accuses me of trying to control her life or grab away my "inheritance"? If I even have one any more--she's threatened to disinherit me many times over the years whenever I don't do as she wants. From the bottom of my heart, thank you for reading all of this!