Are there Theravada meditation retreats that allow one to work for room and board? Practicing meditation in South Mississippi, USA, without easy access to a sangha or teacher, and reading Buddhist literature (primarily Theravadan), I feel a need to attend a week to ten day meditation retreat in accordance with Theravadan practices. I am retired, so my typical daily practice comprises sitting for at least an hour in the wee hours, and occasionally another 1hr+ sit in the evening. I would like to attend a retreat that lasts at least a week. However, I can't afford to pay much money. Are there Theravada meditation retreat opportunities in the USA that offer a visitor the option to work for room and board?
Here you can see the US locations for the 10-day S.N. Goenka Vipassana Meditation Retreat.

This retreat is free and is solely dependent on donations from past students. So a retreat is a gift from a past student. 

You can read more about the tradition and the course here.