I’m sorry for your troubles. More and more I read stories like this that convince me to continue staying away from CVT transmissions…
I’d also like to mention that Nissan isn’t in charge of the maintenance on your vehicle, especially transmission fluid changes. I get the transmission fluid changed on all our vehicles at 3 years or 30K miles, regardless of what the manual (or dealer) says. If your Nissan dealer won’t change the transmission fluid, I’m sure there’s a local shop that will gladly do it.
And I’m no lawyer, but I believe if you have documentation of the maintenance being done, at a dealer or otherwise, then you’ll avoid any potential issues with the factory warranty.
And finally, for what it’s worth… pending the outcome of the current diagnostic, I’d lean toward keeping the Pathfinder and driving it, too. Seems like the better choice. The devil you know and all…
Good luck.