My advice would be to try be in Maryland/Chesapeake by mid October as if later you will be in 'gale season'. From mid-October on you will be subject strong NW gales ('equinoctal gales') that can keep you 'in hiding' for several days. During this time (late September, on) Id avoid rounding Cape Hatteras as its a 'birthing site' for the very rapid formation of Lows/storms, so If running outside Id come in at Beaufort/Moorehead City or Cape Fear and run the ICW from there up to Norfolk, etc. From SC to Beaufort (heading NE) at that time you can sometimes experience a 'nantucket sleigh-ride' on a screaming beam reach by coming in close to shore to avoid the 'fetch' from the NW (watch out for the shoals) at the 'tail end' of a gale.
The 'equinoctals' can sometimes occur earlier depending on how 'early' the change from late summer to early winter weather patterns (watch for the jet stream to begin to flow more 'southerly' on a 500mb weather chart) . Watch the birds ... if you start seeing migrating geese, swans and eagles along the coast you can be quite sure that the weather will soon be 'turning'.