I love your picnic memories, Bridget! I think a solstice picnic is a wonderful idea.
I've spent most of my life in the South where the bugs, heat, and snakes tend to discourage true picnics - the ones where you sit on the ground.
Once, many years ago in my "previous life", my then-husband, my father, and I were working to clear land on which our house was to be built. This was in a rural area about 15 miles west of where I live now.
I packed a lunch for us and after hours of cutting down trees and stacking logs, we stopped to eat. There was a big live oak tree with a wide shadow to protect us from the Florida heat. My father sat down with his back against the tree, not noticing that there was an opening at the base.
As my father munched on his sandwich, the biggest corn snake I've ever seen slithered from behind his back and along his left leg.
My father once owned a lumber yard and was very well acquainted with snakes. He knew the large one that was slinking by was not venomous and not even know to be a biter, so he was not concerned. Still, it reminded us to be very careful where we sat in the future. Years later, one of our dogs was killed by a coral snake in that same yard.
Yes, picnics here require elevation - picnic tables, the tailgates of trucks, something that keeps us above the ground. But, even then, there is no protection for the insects and heat!