Been there, done that. Once the idea takes over, I usually just have to give in.
Can't offer any advice on the laptops. I have no idea how much mine weigh, and they are always plugged in, though I do know they last less than 30 minutes if you are playing a game unplugged.
I'm super particular about my machines. I've been buying Thinkpads exclusively for the last 10 years or more, the Surface Go being an exception because it was cheap and met the needs I wanted it for at the time (tablet functionality for playing tabletop wargames, but with a little extra utility) and it still meets that need fully. But again, I'm a sucker for Thinkpads and getting one that weighs the same, but is more powerful and offers trackpoint is just a complete win in my book.
But yes, I will probably have to inevitably give in and buy one, even though I'll then have 3 different laptops for various purposes, which seems...redundant.