It sounds like the Rivian R1S would be perfect for you. Not sure if you've looked into it already, but it should be coming out second half of next year. I am in a similar boat as you (love the MX, probably won't get another one unless it's significantly redesigned) and I am anxiously waiting for the R1S to come out.
R1S looks amazing. But I'll need more confidence in the fast charging capability first. Can't risk being stranded in a Rivian. Was stranded once in the MX (rolled upto a 3rd party charger that was out of order in the middle of nowhere with 1% charge), at least I was 40 miles from a good, working, well lit supercharger.