Five acres is slightly more land than I have (in the exurbs of Toronto), and is almost certainly much more awkward, with less usable space. I mention that because I can't imagine trying to facilitate the desires of 10 different owners on such a plot, and the practical limitations of such a space will become quickly apparent. Notions of being sovereign and all of that seem really strange -- you fall under just as many regulations (if not, in some ways, more) than a plot on the mainland. Assuming that you will fly under the radar is a dangerous gambit.
To visit this place you rely upon the graces of what is to you a foreign country. A simple DUI or possession charge in the US == barred from Canada. And so on.
Totally get the thought (I have bid on various large parcels of land throughout Ontario), though, just think 5 acres is just much too small.