We're in the process of replacing our second car and that will end up being less than half the price of the Tesla. But if I were going to spend > 60k, I would buy a second Tesla without the slightest hesitation.
In 37k miles I've never experienced limp mode and don't know much about it. I regularly drive for over 2 hours at Midwest highway speeds.
Can you describe your half-day jaunt through the mountains in more detail? I'm having trouble figuring out how this is out of the question.