Down here in VA I surface broadcast a cover crop into standing rr beans when they yellow. The same can be done with corn but depending on stalks you will get less sun. I like a mix of WR, PTT, and CC in my area. WR provides fall attraction and the PTT tubers last well into our winter. The Crimson Clover is an annual clover that is reseeding in my area. So, unlike perennial cover, it comes up much faster and will reseed so it comes back in the early spring. I can then no-till drill next years warm season annuals through the cover crop and spray to kill it. Daikon radish can also be used in place of PTT, but it has a larger seed and doesn't germinate quite as well as PTT for me when surface broadcast. You are a bit north of me but not that far. I'm sure CC would reseed at your home in southern PA but depending on elevation it may not at your camp. Berseem is another annual clover that one could consider.
If you only want a single crop, my go-to in your situation would be Winter Rye.
Thanks,
Jack