For Intel based laptops built in the last 10 years basically the only thing making a difference in battery life for laptops with same CPU is screen, and battery.
Everything else is almost the same everywhere. NVME SSD + WiFi will uniformly eat 2W. Power conversion will also eat at to 500-800mW. All other peripherals combined will unlikely to eat more than 1 watt, with exception of 1GB ethernet if working full speed.
From my desk, to my easy chair, to my bed, and back again.
Not hard on my battery (two of those have charge cables handy) but difficult to pull off with a desktop.
Now that you mention it, it's been more than a year since my laptop has left my home. Ouch.
Granted, becoming a parent also meant that things like watching a movie are “haha, I’m going to sleep” now, too.
I use a sit/stand desk but barely ever sit at it, so fifteen minutes of down time here and there helps.