Well, we're back. And here's my general travelog, mostly going by memory:
Pulled out of the south end of Salt Lake County at 97% charge. Temps were in the 30s-40s the whole trip. Kept general pace of traffic at 75-80 mph. Kept it in Eco mode the whole time. Averaged about 3.2 m/kwh to Brigham City. Stopped at the Walmart at about 72%. I couldn't get my EA app to accept payment from my iPhone wallet at the charger, and got frustrated trying, so I just used a credit card to top to 90%. For some reason the pre-conditioning default turned itself off, so it was very slow. I think it maxed out at around 48 kw. There was a Chevy Bolt at the other 350kw charger. Didn't see anyone else.
The next leg is very hilly, and the speed limit is faster, so my range dropped reasonably significantly. Averaged about 2.7 m/kwh, keeping roughly 80mph pace. Arrived in Burley with about 33% charge. I academically probably would have made it without stopping in in Brigham, but it would have been tight. Sister-in-law's place pretty remote. I probably could have made it there and then back to the charger in the morning as well, but I decided to not roll the dice. I charged at EA, this time having pre-conditioned. I'm here to testify that pre-conditioning is the move, though it does seem to drop the efficiency by about .2-.3 m/kwh for about 20-25 minutes. This time the charger maxed out around 190kw. 33% to 80% took about 15 minutes. Again, I couldn't make the fast-pay from my wallet work, and I used a credit card. Drove to my S-I-L's place and arrived with about 68%. Glad I didn't risk it without topping off. Saw a Mach-E and another EV6 at the charger. The other EV6 couldn't get his charger to stay online for more than a few minutes at a time. He moved over to the one I was using after I left.
I was able to Level 1 charge at her place, so it reached about 85% before we took it to Twin Falls the next day. We spent a couple of hours up there and headed back with around 50%. Decided to not try the ChargePoint chargers in Twin Falls. Preconditioned again, and hit the EAs with about 18%. Never saw better than 3m/kwh the whole time. I didn't try the fast-pay from my wallet this time, and instead went through the EA app by selecting station and charger, and it worked. Not sure why I didn't think to do that in the first place. My bad. Pre-conditioned again this time. Topped off to 80% in about 30 minutes and then headed back to S-I-L's place, and plugged in at Level 1.
This morning we had a couple of errands to run, and I hit the EA chargers before we left town. I was at 74% and planned to charge to 100% before we hit the road. Things got away from me and I forgot to pre-condition again. So charging was VERY slow. I should have taken the 150 kw charger, but since no one else was there, I didn't think too hard about it. Maxed out around 33kw, but probably averaged closer to 25. When I arrived I was the only one there, but while I sat there a Model 3 pulled up and took two spaces to charge so the cable would reach his charge port (weird, because there are Tesla chargers a couple of miles down the road.) A Mercedes EQS pulled up and took the other spot (where I saw the EV6 the other day who couldn't keep it online). He got out and eyeballed the Tesla guy pretty hard, because he was blocking the other 350 kw charger. I gave up at 95% and we got on the road. Probably good, because the EQS guy went into the gas station didn't get a chance to see how slowly I was charging at the "hyper speed" charger. I hope he moved over when I left. (Also we watched a Model Y block a fuel pump for about 40 minutes while she walked her dog around. Even though there was plenty of parking elsewhere.)
By the time we actually got on the freeway, we were at about 90%. The stop in Brigham was not academic this time. I saw around 2.6 m/kwh. Pre-conditioned and rolled into Walmart with about 35%. Charged to 80% in about 17 minutes. Maxed around 190 kw, but averaged closer to 120. Got about 3 m/kwh the rest of the way. Arrived in SLC at about 45%.
Disclaimers: I'm going off the best of my recollection, I didn't keep written or accurate notes. If my numbers don't completely line up, I'm probably just not remembering them exactly. I know I could have slowed my speed down to increase range. I decided to accept the lower economy to not be in the way of traffic. I got passed by an Ioniq 5 at one point who must have been going 90. We didn't use the climate control extensively, it was set to 68-70 degrees most of the drive, and it never got warmer outside than about 45 degrees. Ventilated seats are very nice on long drives. I used cruise control for the majority of highway travel. I'm not sure I like the lane-keeping feature. I felt like I was wrestling with the car a lot. I definitely don't like letting it change lanes for me. I do like adaptive cruise. We had two adults and one adult-size child in the car. On the way home, we had about 30 bottles of wine which might account for the slight decrease in range on the way home. I'll be curious to see how my efficiency is changed when it's warm. We will be doing it again in June.
[Edit] Should note I also had the regen on auto the entire time.