It has been done. But, you have to remember to really pick your days. This passage is across the Gulf Stream, which against the Northerly winds, make very steep and dangerous seas. I have friends who have to wait weeks to find the right day to cross with 50' boats. Have plenty of days, cash and patience, plus a cast iron stomach.
My own experience is in 26 foot, 46 foot and 62 foot sailboats--the latter two which I have crossed oceans with, and had seas up to 40' feet and breaking--not C Dory weather.
I have run in 6 to 7 foot seas, down wind...I would not try it in beam or head seas in a C Dory 22 or 25.