My bride and I took our boat from Ft. Lauderdale to Chester, Nova Scotia, in 40 days. We generally went 14-16 kts. and mostly on the outside (more use of autopilot, no wake complaints). Fog set in at Norfolk and pretty much stayed the rest of the way so this cut us down to hull speed, 9 kts. Since this was supposed to be fun for us we stayed in Cape Canaveral for a shuttle launch, Manteo NC, Boston (at the old Long Wharf downtown), Newport, Southwest Harbor ME, maybe some others for two days or so and stayed in port if the weather was rough. We could make 100-150 nmi. per day. Most nights we stayed in marinas because we needed to refuel and wash the boat. We would leave at dawn and tried to be at a fuel dock by 4 in case we would have to divert to another. Amazingly we didn't get lost, didn't hit anything and never ran aground. It was just a great trip. The return was about the same although we added NYC, Washington D.C., Delaware and Chesapeake Bays with more sightseeing since now we could estimate the trip better. And rode out a hurricane in St. Michaels, MD.
If I were a real delivery captain and not a sightseer I would estimate this trip would take about three weeks, weather permitting and not running at night. But then we would have missed one of our best adventures ever!