Just to circle back on this: I don't really have much usable data for this. I had a longer trip at the end of November, but my battery died right before the trip, so the ECU was in learn mode for half the trip or so. Also, I don't ever get on the highway unless it's for a road tip. This isn't a daily driver, and when I do drive it to work, it's about a 3 mile trip. Errands around town are similar in distance. At any rate, on the way home from Central Oregon, we hit snow and drove in 4WD for about 30 miles. I got 171 miles out of a half tank of gas by the time we got home. I averaged 16.8 mpg on that tank as I finished it with short drives around town. I'm pretty confident that 300+ miles per tank is doable with long distance driving. That's by the time the light comes on. Tank fills are around 15.5 gallons when the light comes on. It's not on "E" when the light turns on, but slightly above it. I'm certain the sender unit is accurate.

As I drive this thing more on longer trips, I'll update this. We are going to the coast on NYE.