The likelihood really depends on how you follow the regimen and mitigate the chances of failure by learning where others failed in the past like being found, not following the regimen, the crucial thing to remember is that any significant misstep is something you may not be able to compensate for.
With just SN +Meto, that is the basics of what you need however if you can, I'd say adding benzos is rather beneficial and some kind of painkiller.