I've just punched this up in ABRP and I disagree with it, as usual, but it's at least marginally informative.
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ABRP allows you to set all kinds of conditions, such as outside temperature, headwind speed, road conditions, and then preferences like what % you want to arrive at Superchargers and your destination.
I gave it pretty bad conditions like a 10mph headwind, 20f temp, rainy/snowy roads, and driving 110% of the speed limit (you have a Performance, I suspect you speed
).
Charge to 100% (or near enough) before leaving home.
ABRP thinks you can get to The Dalles with a 30 minute stop in Kennewick. I think it might be less. Depends on what you want to arrive with and what actual conditions are like en route. The car will tell you how long you need to charge, or when you are able to depart and arrive at the next location with enough battery charge remaining. During winter trips I usually click the "continue trip" button in the Navigation and wait for the next arrival percentage to be 15 to 20% for plenty of winter buffer.
Another 30 minute charge in The Dalles to get charged up to return to Kennewick. Same same.
ABRP then states you will need to drive slower on the trip back to Pullman. Without looking I'm guessing Pullman is plenty higher elevation than Kennewick, which would instigate that kind of calculation result. It says to charge to 99% in order to arrive at 8%. ABRP does a fair amount of padding in order to be successful. I would still charge that much, but anticipate arriving with plenty more juice than that.
The car will recalculate arrival percentage during your drive. You can adjust your speed to accommodate the arrival percentage. On longer segments that I'm unsure of I tend to drive more conservative the first half and once the percentage seems pretty well locked in I might pick up the pace if I'm comfortable with what it's showing. Especially returning home where I know I can park the car and let it charge overnight.
Arriving at a Supercharger or home with a small battery percentage is fine. You aren't going to damage anything. The car is pretty good at estimating those values and if it says 3% it's probably going to be 3%. Learning to trust this tech can be a big hurdle but after you've done it once it starts to make a lot of sense. The car takes into account known elevation changes and other static affects on range. You can see this in the consumption/trip graphs.
I suspect not a lot of people have driven a Tesla out that way and if there's any truth to the shared machine learning then that data may be a little less accurate than the data for the section that is I-84/I-82.
I think you will have no problem making the trip. For cold weather I recommend waiting for the Navigation to show 15 to 20 % for the next destination arrival. Keep an eye on the arrival % while driving and slow down as necessary to ensure the arrival % is adequate. Head winds are the worst. I know it gets windy out there.
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