Feelsbadman

I hit it years ago and have to delete swaths of pics every now and then to make room

A good habit to get into once you.ve hit the limit/are close to it is to do a single stroke with the eraser when you start a new canvas then save the canvas

If it saves, you can resume work on it, if it doesn't save you'll know to ditch it and go delete something. Doing this keeps you from starting a canvas and drawing (something possibly really cool) on it then not being able to save it.