Twice. Vipassana is all over the world. It's hardcore but doable. The second one I did a decade later. Was with Tibetans and was more "relaxed" in the sense they taught more and could read, do yoga, other mindful things during downtime. Vipassana is almost all meditation with a little teaching. 

Have you done one of these retreats? What was it like?

Signal312

AskSN

Do We Still Know How to Be Bored?

hasherstacker

I think the loss of required boredom/silence is a huge loss. This is one reason I think mindfulness and meditation practices can be more helpful than ever. Doing a 10 day meditation retreat with no technology is a wonderful experience. 