My own garden is following suit. The leafy greens, to which makes up most of the garden, aren't growing. I just pulled the entire lot of mizuna mustard, since they were still very small plants (about 1" leaves), but already started to bolt. When greens flower, their leaves become bitter.
But 2 of the plants seem to be loving the cool weather: arugula and peas. The peas were an underdog plant: I planted the seeds very late in the season, only because I had an empty space and figured I would give it a shot. Now, it's my favourite plant. I love how the plant grow arms that hook onto nearby sticks for support, and how the peas poke out right from the flower.
Moral of the story: biodiversity is good. But you knew that already. So if you have the space, grow a lot of different plants. When Nature acts unexpectedly (and she will), your garden can adapt much better.