I found only three potential options for completely wireless.
Ring Spotlight Battery, Arlo Pro 2 (from Netgear), and one called Reolink Argus.
Ya I don't expect much from a wireless camera. At best, if it's online, we'll get a few seconds of recording, maybe some snapshots, and an alert sent to our phones. That's all they are trying to cover on the cheap, with fast setup.
As for the building lease, I don't care. It's a two story building, metal studs, stucco, firewall between stories. Just a mess for wiring. A mess for drilling into stucco too. We are out of lease period now so boss is afraid to bother landlord lest they decide we have to reup the lease and wants to charge a lot more!
I'd love to do a full security camera setup here but with wiring and hardware it's many many thousands of dollars. And that might get in the way of xmas bonus, just saying.