i.e. if you're tired of the cloud, get a local controller and rehome the cameras. All you stand to lose is past footage.

I'd be more worried about the cameras hanging out on the internet without knowing if anything can get to them. That's how the Mirai botnet came about. A local network video recorder is small and can be easily concealed (a secondary PoE switch can power+ connect the cameras so the only lead to the NVR is a single Cat5 cable.)