No need to fixate on V3s either, V2s will do just fine too and you will not see 200-250kW for long while charging anyway.
V3s are way better. They're more reliable and consistent in their charging speed, because they are newer, they seem to start charging faster, they deal with temperature better, there's essentially no sharing with other users, etc. I've had ample opportunity to compare them at this point.
Should always hit V3s if you can, and they are definitely worth fixating on if you're interested in fast travel. Obviously you don't go out of your way for them.
For the OP, yes, the right idea is to drive down to about 10% (you can really blast at the end to try to make it there at 5% if you want) and then charge up just enough to make it to the next stop according to the car; I'd recommend
5-10% margin vs. what the car says, just to be sure you can drive there as fast as you want, because it does tend to tell you to leave a bit too early (wait until the car says you're going to arrive at ~15% is probably best). You can adjust this margin once you're very comfortable and familiar with how things work (and account for weather conditions, or any conditions that could affect results!). If you're confused about why your usage varies, then you should maintain the margin. It just takes a couple extra minutes and reduces stress until you're familiar with how it works. Use the navigation in the car. It is quite good, but use it just for charger to charger, not for the entire trip (it is quite bad at that, since it does not minimize trip length; it seems to minimize the number of stops instead!). Remember that you can click the supercharger icon in the lower right to bring up all the superchargers, and then click it again, and you will not lose your current route. (This is an interface issue that is fairly confusing, especially when driving, but once you know it, it is no big deal.)
Basically, when using the navigation, you have to tell it which Supercharger to stop at, if you want to have optimal travel time.
Also, is there an easy way to determine where the 250kw chargers are? Can't seem to figure out how to filter for that on Tesla or ABRP.
Regarding 250kW SuC in ABRP. I don't know of a way to filter to 250kW (maybe there is?), but in most places in the US you must charge at some 150kW chargers on a journey (California is starting to become an exception in some places). However, ABRP does provide the information on which is which (have to click on the station), and you can choose to avoid them when trip planning in ABRP if it makes sense. However, it doesn't make sense to avoid a 150kW station if you have to charge to 95% to make it between two 250kW stations, due to the extremely long charge time at the 250kW station to get to that level. You just have to do what logically makes sense. ABRP is pretty good at it but can be slightly pessimistic.
I looked at the route to Portland, ME, just briefly. There are enough 250kW chargers there now that it may well make sense to try to hit them exclusively, for certain segments of your trip, but I didn't look in detail because I don't know the exact itinerary. ABRP did NOT exclusively hit them when I plugged in the trip, and it is trying to minimize trip time. But I don't think it necessarily adequately accounts for the penalty for visiting a 150kW Supercharger when utilization is high. As I said, just have to take a look and see what is reasonable. I assume you have a 2021 LR AWD. That should give you some additional flexibility to have the 250kW Superchargers make sense.
If you're traveling at a time when utilization is high, familiarize yourself with the in-car interface and how to change up your plans if utilization is too high at some Superchargers (or if there is limited service!!!). No one wants to wait in line to charge. However, in that sort of scenario, there are huge benefits to 250kW, of course, due to lack of sharing.
V3 FTW! 150kW are ok as long as it's not busy and you can rapidly switch between stalls - switch (extremely quickly of course) if you aren't seeing over 140kW within the first 30 seconds or so (assuming you're below 50% SoC of course). Also make sure it stays there (within the limits of the taper). Sometimes they'll start fast and then suddenly crap out - the V2 are pretty annoying overall!
BTW: Be sure to always navigate to Superchargers to ensure the battery warms properly.
At night, or if it's dim enough during the day, keep an eye on the lights on the Tesla logo on the pedestals. If they're off, the charger doesn't work. Happens all the time.