Son of Jor-El
I've played it as move your dudes FROM other locations TO Piney's Cabin.
This makes sense to me thematically as it is a place that the Sons congregate at after 'shit goes down' in the show. In game terms, it allows you to gather your crew for whatever reason - reinforcements, throwdown etc.
^^ 100% this
The boost action on the I-5 Corridor location does your other suggestion (move any dudes from that location to another one.)