A suggestion-- can you let the financial stuff go until after the holidays? I feel like Christmas etc is ALWAYS stressful no matter what with so much stuff to do, and then throw in all the anxiety of being S and the impact of that on the children during this time that is supposed to be so magical and fun... I wonder if that is adding to your frustration and anxiety and pushes you towards wanting some movement.
I also ask if bringing up selling the house is more about how she might react than about the actual $$ (not that it isn't a serious issue)-- since she seems to be OK in the current situation, pushing on the financial front would be a dose of reality for her? Not that reality isn't a bad thing, but I wonder if you're subconsciously wanting her to feel more of the hurt of what is happening. And, with her history of painting you as an unfit dad, I wouldn't want to necessarily add something major to her plate during this already super stressful time since she's liable to respond more poorly than she would otherwise-- and that could potentially impact her attitude towards your time with the kids. (As well as how well she's able to parent them.)
Anyway, just wondering if you can figure out how to put this all to the side until after the holidays. A few weeks won't really matter in the long term and it takes some of the pressure off. Freaking your W out and/or filing at Christmas just doesn't seem like a good idea in the long term. I'm thinking about this myself-- focusing 100% on giving my kids the best Christmas and holiday I possibly can. They're only this age once.
(Funny how advice is so much easier to give to other people than to implement oneself!) You're doing great.
Me (46) H (42) M:14 T:18, D9 & D11 4/19 - 12/19: series of escalating BDs 9/20 - present: R and piecing