I've got a 750w and it handles hills pretty well. To the point where you don't need to actually pedal unless it's a long steep one but even then it's like pedalling on a straightaway (using pedal assist is of course is always optional).

Before I got the bike I wanted the most powerful one available but I realized after getting one you don't really need that. And it's actually kinda dangerous, even for a experienced cyclist who's used to speed.

Even the standard tier batteries are more than enough for any urban biking in terms of distance. I rarely use even 20% at 48V, 10.5A.