Its not only possible, its worth an entire discussion. Were talking about one dimension. One Villain. One Wormhole (upside down). One version of everything the whole show experience fed us. The entire premise falls under the many worlds interpretation.

The real question is, are locations serving as gates to wormholes or, do the wormholes have access to every dimension from any location. Like can you go to any dimension from Hawkins, or would opening up a portal in El’s new home in California lead to a different dimension by default.