Yeah, Alexander's Lodge comes up a fair amount when I was researching this. Overall, the trip is like, barely doable, but then you have to consider that from Ohanapecosh (one of the major campgrounds) to Sunrise (where a lot of hikes start) is 30 miles, so in a 2-day trip, that could easily be an extra 60-120 miles of driving. On longer 3 or 4 day trips, I've sometimes needed to drive out of the park to Packwood to fuel up, because the park is so spread out. BTW, when I was looking in A Better Route Planner, it recommended driving up to the supercharger in Centralia, or even driving all the way up around to Enumclaw (IIRC), which is
way out of the way.
The ideal (for me anyway) would really be to have a supercharger (or other fast charging) at Sunrise, and ideally one in Packwood as well. Or forgot the whole enterprise altogether and put in a bus service like Zion has.
Of course, Rainier is only one example. Once you get into Eastern Oregon, the charging situation is even worse.
I would hope that if we get a more forward-thinking government in the next few years that we start thinking about this kind of stuff, because thinking about the carbon impact of "enjoying nature" is pretty bleak stuff. I'm actually interested in this problem enough that I've started to look at the economics of building charging stations (demand charges!)