I do like me a nice UPS, but perhaps the idle consumption of a UPS is a bit high for a laptop as it’s only protected load.
I think most of us in the creator space are waiting for some parts to be easily available in order to solidify the measurements of something like a battery in a 3d printed case. There are a couple threads that introduce interesting concepts and promote the creation of a DIY battery case. Until a few more laptops have been shipped and the first batteries go up on the Marketplace for sale, it seems we are at an impasse. Good luck on your search!