My parents lived in a commune back in the 1970s. People were not clean in there, even with a fully working society around them.
They also got a lot of freeloaders and some people who were there to take advantage of the work others did (which is probably why they shoot people who try to come in so easily, freeloaders are worse than the infected).
Not to mention that most had to be on welfare to get money so they can buy stuff produced on the outside.
Now a 300 people village doesn't produce that much, without big machines most will end up farming or hunting (and after a very short amount of time there will be plenty of animals to hunt because there will be few humans left).
My parents left because that did not work.
Either way, I think a lot of these communities would spring up here and there, given the small number of people it would make little sense to even have money. For trade, but the system would likely end up to be like feudalism/servitude (which is what communist is like in practice).
So overall it kind of work.