https://jretreat.com/If you are ok with a mixed crowd of Chabad House people, there's the JLI retreat in Trump Doral Miami this August.
I attended in the past, and it's an amazing retreat with tons of interesting classes, entertainment, and top-notch food.
The food and shul are up to Chabad standards (Chasidish Shchita, full mechitzah.) And there are a decent amount of frum people there as well.