Any amount of edits. Even if you stop paying, you can still access your edits, you just can't use Develop anymore.
There seems to be some mysterious cloud hanging over the subscription plan. When you sign up, you install Lightroom and Photoshop locally on your computer. They are local software programs, running like any software program will run. There is no reason for you to think that there is any kind of limit to the number of edits for anything else that you can do with the software. It's on your computer. And you can do what ever you want with it.