I'm at the tail end of the trip, on the way back home, currently at the hotel next to the Worthington, MN Supercharger. This was the only place where I experienced ICEing, on my way to Yellowstone. I was done charging, parked in the hotel lot, and had dinner at the Ground Round restaurant hosting the SC. When I came out of the restaurant, I saw a truck with a boat perfectly blocking all 6 stalls. I complained to the restaurant that the truck was blocking all the charging spots, even made it clear that I didn't need to charge but was "covering for other owners who might need it", they found the guy and made him move, then about an hour later when he was leaving he complained to the front desk that I didn't charge my car and I made him move for nothing. My car was parked on the hotel side near the SC and I saw a couple of his buddies standing next to it. I didn't see any damage when I looked after they left, but the experience convinced me not to complain about ICErs in the future unless absolutely necessary.
I had no issue at all with range in the park itself and charging at the Emigrant house on 113V 12A worked very well with our plan to just stay at the house most days and go into the park twice (Old Faithful and Canyon Village) during the week we were there. At one point on the way back from Old Faithful, after the last stop, I achieved 48Wh/mi for about 20 miles of driving mostly downhill. For the Old Faithful trip, I drove 177 miles and used 163RM (82%). For the Canyon Village trip, I drove 149 miles and used 140RM (71%). The curves in the park were a lot of fun to drive through, maybe even more fun than the geysers (the sulfur smell doesn't help their case).
The major challenge on this trip turned out to be the 80MPH stretches of I-90, which the trip planner predicted horribly. On several occasions, I charged at SCs until the trip planner predicted I would reach the next SC with >20% (charging until about 90%), then within minutes of getting on the highway and going 70-75, the prediction tanked by roughly 5% and continued dropping until I had slowed down to 61-68MPH (in the 80 zone). Today, when I reached Minnesota and the speed limit dropped to 70, I noticed the predicted % increasing, so I bumped my speed up to 70 and the predicted % remained stable.
Interestingly, on the way out, the only SCs where I saw other Teslas were Ann Arbor and La Crosse, plus a couple seen from the hotel in Worthington. On the way back, I saw at least one at every SC from Big Timber until Murdo, including the first two or three production Model X's I've seen. First X was at Billings, a black P90D with a temp tag from Colorado, whose owner I spoke with for a bit. Second was a blue one leaving the Rapid City SC as I was arriving, which may have been the same one I found at Murdo with an Illinois plate, which IIRC was also a P90D. I also noticed two S owners getting some good Tesla Time at Big Timber and Murdo.
Anyway, I've said enough for now and I may have more later once I get home. Of course, I'm open to questions.