I did the dismal this time of year single hand three years ago in my Flicka 3-3 draft, Overnighted at the visitor center. Was eaten alive by no-see-ems that night. Just protect yourself. It's the route I would take again ! And E City a great stopover.
My boat has a 45' mast height and I had no problems with overhanging trees. No need to unstep the mast. I did get into some tree branches at the Visitor's Center taking a too-direct route to the end of the bulkhead. But the water spigot was right there so I just hosed down the deck. There was one fallen tree we had to dodge, ironically less than a mile from the canalmaintenance area.
Did you know the canal was dug with slave labor by hand?
2 years ago we transited the Dismal swamp. 56 ft. mast 5'4'' draft no problem.
Nice trip and the lock tenders were most friendly & helpful. Timing the locks is important if you are in a hurry. I also recommend the visitor center they also have showers etc. there.