Thanks, guys.
Sound advice! I'm not sure how strong an alumni presence my fraternity has in the non-chapter school's area or indeed even in one area that has a chapter (due to chapter's newness), but I'll definitely look into that once I know for sure where I'm going.
And I'll definitely get to know fellow graduate students who are Greek at the very least.
Point well taken about the advisor/chaperone feeling.... and I certainly wouldn't impose myself on anyone.