Battery range for long commutes

Hey everyone!

Been loving my new e-gravel bike for my commute, but I'm starting to wonder about battery range for longer distances. My round trip is about 25 miles with a few decent hills, and I'm finding I'm usually down to 20-30% on my 500Wh battery by the time I get home, even on eco mode. For those of you with longer commutes (say, 30+ miles), what kind of battery capacity do you find is truly comfortable for a round trip without range anxiety, especially if you've got some elevation gain? Do you carry a spare or just charge at work?