We were there a few weeks ago. We've been lucky, all our trips up and down DE bay have been during calms, so major issue was hitting the currents right. I say lucky in that DE bay's reputation is bad.
Remember that the railroad bridge on the C&D
canal has only 45 ft clearance when down. I assume from the size of your
boat you can't get through the
canal into Cape May harbor, so you'll have to plot a course around the cape (this year was our first trip where we had to go around; of course squalls caught us).
Don't know of any issues specific to this time of year, but the daily forcast is important.