Great idea ... June is fine ... maybe Thursday or Sunday
evening when it's not as hot and crowded ... between 6-9pm? BYOF is another
good idea as I think cooking can be a hassle.
I went to a Meetup at Deep Eddy not far from Zilker (relatively
central) ... picnic tables, beautiful lawn area and it seemed like a
very nice place with a huge swimming pool. It's free too. However, I don't know
about fees for the pool. Parking was pretty good (free) although nothing was
going on when we met.
Fun and games ... volleyball, music, possibly bring a couple
Just my $.02