I'd never claim there are no limits. I do believe that we can't predict now what those limits will be.
And here you touch on one thing that no one has mentioned, other than a passing
tongue-in-cheek post by
@ElPaso Pilot. The final solution may possibly be a vastly improved battery technology that we haven't hit on yet. It may instead be some other source of electrical power that we haven't even thought of yet.
Lest you think I'm some kind of sci-fi dreamer, no, I don't think we'll see some miraculous dilithium crystal power source... not any time soon, for sure. But I grew up in the 60s and 70s, and started a career in what we now call "IT" at the very dawn of the 80s. Most of what we have now would have been dismissed as wild fantasy and totally impossible back then, including driving my car (with heated and cooled seats and a couple hundred channels of 24/7 uninterrupted music) at 80 miles per hour while getting close to 30 MPG. I'm sure automotive engineers in the 70s thought they were getting close to the best that could be done, too.