Even if we discount members of Congress and their staff's not being permanent residents in DC. Its sort of a moot point. There have been permanent residents in DC from the beginning and it sort of couldnt function without at least some.

Those boarding houses and hotels which many members would cram into when in session had to be owned and operated by someone. The Washington Navy Yard was the Navy's first shore establishment when the land was bought in 1799. As a major employer of both enslaved, and free blacks, and of course whites and skilled tradesmen, it could not have functioned without a workforce close at hand.

While Georgetown and Alexandria both predate the establishment of the District on either side of the river. The area was always going to lend itself to settlement because it is the farthest up the Potomac that a large vessel can with only some difficulty navigate before you run into the Great Falls of the Potomac, and in the days before the the construction of the C&O Canal that meant it was the closest you could get to anything coming from the Shenandoah or Allegheny's and the town of Cumberland MD. In fact the Patowmack Canal was the first attempt to get around them begun in the 1780's even before the establishment of DC. Part of it is left today and can be seen at the Great Falls National Park.

So unless you wanted to demolish the existing river ports of Georgetown and Alexandria(prior to Retrocession in the 1840's), there were going to be permanent residents of the District, because they were there first for reasons of geography and economic necessity.