But you're not doing burnouts, speed shouldn't make a great deal of difference other than the faster you travel the better your tires should be. I know I have to pay more for Z rated tires.
I never agree with the automatic headlights choices. I shouldn't say never, but often disagree. I can tell if there is a vehicle approaching around a blind bend or over the crest of a hill at night. The lights won't dim automatically until it sees his lights and by then he's caught my high beams full in the face. I try to dim them before that.
If you start out in the morning with a full charge and if you don't need heat or chill, and you drive slow and safe, then you're good 280 miles. That's a bunch of ifs to take into account without looking at a fuel gage.
But none of that matters because it's what you've wanted for a very long time and now you've got it... plus next year you'll grab the brass ring and live happily ever after.