Hi Roberta,
That sounds amazing! We've been living in our travel trailer for a whole year now and love it so much, but we definitely dream of downsizing further in the future and would love to try traveling in a van someday.
At the Osho ashram in India I met a few volunteers who had live-in positions there and they highly recommended it. It wasn't all Vipassana courses, though there were some Vipassana courses available, but they had a lot of really fun dynamic meditations. The Kundalini meditation there was my favorite! I would love to do a 10-day vipassana course sometime though. I'm looking forward to seeing how you like it! <3