If you have a medical recommendation and can find a property that meets the requirements, then yeah, you can do 25 plants with probably not a whole lot of risk. A garden that size is much too small for local law enforcement to mess with, unless they get a complaint called in. Of course the regulations don't stop a lot of people from just blowing up massive gardens wherever or setting up trespass grows out in the National Forest. There is also no guarantee the local police won't hassle you, Mendo has it's fair share of incompetent and corrupt cops, some of which absolutely do not give a shit if you are 'legal' or not.
So I wouldn't say it's quite that easy, good grow properties are scarce and usually expensive and there is definitely going to be a rush on them here now that it is clear we will be one of the counties that will have legal commercial cultivation in 2018. Not to mention all it takes is one bad or crazy neighbor to ruin your whole scene. Plus law enforcement and most of the locals, even other growers, tend to have a very negative view of new arrivals moving out here just to grow. It is very much a 'good old boy' network that runs things around here - if you or your family have been here a long time, you will have an easier time not getting hassled. If you're new and from out of town, good luck....