Might there be merit to a semi-tethered approach? Enough onboard batteries to last a minute or two when you walk to another room, where you promptly plug in again?
The portable exoskeleton is a pretty big leap though. I think in order to have it be useful anywhere else but at home it would need to be significantly longer on the order of hours. I'm thinking time it takes from getting out of a car to go in to a shop and run an errand and come back (perhaps extra battery packs in the car or a place to recharge from the car)