I get 420-450 miles on a full tank doing 75-80 mph on the highway.
Even if your trip was all stop-and-go city driving, 250 miles would be fine on a full tank. If it’s mostly highway at 60-70 mph, you’ll probably see high 300s.
Set your cruise control at 70 mph, and you’ll get around 425 miles per tank.
Highway driving in my 2018 Forester usually gets me about 400 miles on a tank.
What’s your backup plan if you need to stop for something besides gas or if there’s an issue during the trip?
I have a 2019 Forester too, and I usually get 425-450 miles on a tank with a mix of curvy roads and highways. You’ll be good for your trip.
I just drove 435 miles without refueling and still had about 30 miles left before empty. That was about 7 hours of driving with a couple of quick stops.