The point is that the 150 mile range stated is extremely optimistic IMO because my range was 112 after making many adjustments already to increase it to that number, including driving slower, taking back roads that are slower, and using the heat sparingly. Coming up 25% short of EPA range after making all of those concessions on what is a very average typical weather situation tells me a lot of people will be disappointed in the range.
I'm fairly sure that the EPA range test doesn't involve driving 75MPH in the rain. There are people living in areas with dangerously high freeway speed limits who think that going too fast is the norm, and that this norm should apply to the rest of the country. I get that having everyone else driving 75 or 80 makes it hard to drive 65, but the problem still lies more with the speed limits and lack of enforcement than with the EPA range test, which has improved in the last few years. Although it should include a Winter rating...
OP: Welcome, and thank you for driving electric. Please input your approximate location into your profile so that we can help on other questions (I'm not sure if Sutherland is suggesting NE or TX or nothing at all). So, here's the EPA test: (https://www.fueleconomy.gov/feg/fe_test_schedules.shtml
As LeftieBiker said, it doesn't even get close to 70-75 mph, rain or not. Actually, I think you did pretty good for such speeds and conditions. The EPA "real world" conditions are for mixed City/Highway use in "Low speeds in stop-and-go urban traffic" and "Free-flow traffic at highway speeds" Top Speed: 56 mph city and 60 mph highway with an Average Speed 21.2 mph (city) 48.3 mph (highway). Unfortunately, those EPA numbers are NOT even close to your drive and probably will never be close to the way most people drive. The 21 mph in the city is about my average (yes, those stop lights really do cut the average down to bicycling speeds), but most free-flowing highways are at least 65 mph. I still think that on a 80 mph interstate you can still safely drive 60 mph. Don't try to give me that crap about "everybody is doing 90", cause it's not true. There are always slower drivers and trucks, even in CA.
Unfortunately, you probably won't be able to make that drive in 2-3 years (depending again on location and conditions during the drive), especially if the 40 KWh battery degrades at the same rate as the 30 KWh battery. Those are the facts sorry. Physics matter and high speeds, low temps, and wind/rain/snow cut range, sometimes in half. If that's a problem, then you have the right to send another $15 to the oil plutocracy. Personally, I will NEVER buy gas again, and I will gladly go a bit slower to make my next destination. Unfortunately, at this point in the development, no EV is really capable of long-distance travel except Tesla (which is still lacking in some areas), since such travel requires thermal protection of the battery and properly-spaced quick charge stations. This does cut down on my options, so I'm waiting with my 40-50 mi City 2011 Leaf. This weekend I'll test drive the 2018 Leaf, but I'm still waiting until the longer range 60 KWh version is available.