Considering a Midea 8,000 BTU U-Shaped AC to cool only the bedroom at night

I’m considering buying a Midea 8,000 BTU U-Shaped Smart Inverter Window AC for our main bedroom.

We have a fairly large house, but it’s just my wife and me, so cooling the whole house every night and evening feels pretty inefficient. My thought is that we could use a smaller, efficient window unit in the bedroom and let the rest of the house stay warmer when we’re mostly just using that one room.

This isn’t strictly EcoFlow-related, but one nice bonus is that a smaller inverter window AC could potentially be run from a power bank in a pinch, like our spare DELTA 3 Classic. I wouldn’t expect to run it forever that way, but it could be useful during an outage or for short backup cooling.

Has anyone here done something similar to save on their power bill? Did cooling only the bedroom at night make a noticeable difference? And has anyone tried running a small inverter window AC from an EcoFlow unit?