Cant find a place to stay near Harrisburg, PA, help!

Also, sometimes the Elks and similar groups (Moose, etc) allow fellow members to camp onsite (so you might need to join) but maybe that could be another outside the box option if there are any of those in that area and maybe check if there are any fairgrounds in the area, they may also have some campsites too. Plus, some hotels and such may also have options for trucks/RVs to plug-in (ie- I have heard of some in ski towns in VT that allow RVs to plug in overnight.)