I would suggest creating a new email or using a Gmail disposable email address (ex: myemail+sxsw@gmail.com). The amount of emails that I still get from all these events after attending SXSW last year is ridiculous.
How many of the places actually check their rsvp lists?
I don't think it's supposed to help the host(SXSW). It's expected to help the guests of SXSW plan their day while at SXSW.