A lot will depend on how frequent the good time are, and the income level you have during them. Most agencies require tax reports from several prior years to see if you'll qualify for subsidized housing. In most areas, the need is so great, and the supply of affordable housing so low, that a family needs to have chronically been at poverty level for the past three years in order to qualify. As an example, a family of four would have had no more than $22,350 in income. Once a person is in public housing, if their income increases, so does the rent. But you have to be at the low end of income to get into those units in the first place.
However, it never hurts to apply! And even if there's a waiting list, ask to be put on it. They may tell you it's going to be several years on the list, but people move, and drop off the list for other reasons.
Also, if anyone in your family has been declared disabled, that may give you some priority on those lists.
Here's a link to the federal agency that controls subsidized housing in your state. http://www.hud.gov/local/index.cfm?state=va&topic=renting It has links to local resources as well, and will give you the most up to date information for your area.