I’d be interested in the source of that information and what details or circumstances that’s supposed to describe. My experience with a microSD card of sufficient size is that I can get at least a couple of weeks’ worth of continuous recording, depending on the camera. Subscription status (even lack of a subscription) should have nothing to do with your microSD recordings.
This part of your post puzzles me a little:
If you’re going to do continuous recording, then I’m not sure why you wouldn’t just enable motion detection to potentially make events easier to find in your timeline. (Maybe it wouldn’t make things easier if the area is regularly busy.) I think @StevenA’s question about Wi-Fi availability at your intended location is a good one, too.
Welcome to the Forum, @nvalias4! 