This approach to early retirement largely relies on paring non-essentials from your life and recognizing how little material wealth you really need to be happy and satisfied.
It's an interesting ideology, but in its extreme form it goes hard against the grain of our culture and requires strong will to sustain. And in my experience it's hard to find a partner who buys into it.
I don't think early retirement is at odds with Stoicism, certainly not if its method includes a large amount of introspection about what you actually want and why. Read the forums first and then come back to say if they are Stoic or not. Especially the Lifestyle and Inspiration subforums, :)
In any case the request was for "more Stoic-oriented" forums, not necessarily "the most Stoic" forum.