When contemplating minimalism, I really think the term should just be replaced with enlightenment. Bear with me here..
Not that those who live in crack houses (like onlinemoniez, not hatin bro) are more enlightened than those who live in mansions bc that just isn't the case. It's that much like money is a means to an end.. so is minimalism.. so is materialism.. with happiness, of course, being the "end". The conclusion that we all must come to, regardless of what means we choose to get there, is how to control/train our minds.
What evolution gifted us ( by eating fucking animals god dammit

) and what separates us from the rest of the animal kingdom is our advanced neocortex that allows us to anticipate the future. This is why we know not to chase cars and dogs don't. Paradoxically, the neocortex is also what causes the incessant "noise" in our brains that so many of us wish to silence. We all choose different external factors to achieve this, when in reality, it can be achieved in a crack house in the Bronx just as easily as it can be achieved in a yacht in the Bahamas (depending on the person, of course).
The brain forms it's pathways through repetition, just as muscle fibers are trained and formed through repetition. Therefore, you can achieve your desired mental "peace" through repetitious training much in the same way an athlete can achieve their physical goals through similarly structured training. It's just that it happens to be much more difficult to do so. Either way, whether you have ten lambos or a mtn bike really doesn't matter, and to focus on these things is actually a detriment to the process, but we have trained ourselves to identify with these things and thus "minimalism" becomes a function of something that it is actually completely unrelated to.
Not preaching bc I don't practice what I preach.. Just my 2 cents.