It can be great fishing/boating or you might never take the boat off the trailer due to weather.
From Dec-Apr our fishing is controlled by fronts that come through. After a front comes through (one came through this morning) the wind swings around out of the NW to N to NE and seas get rough. Only idiots go out. As the wind swings to the east and southern quadrants, things calm down and if we can get a break between fronts, the seas calm down, temps come up and fishing is good. Then the next front comes and the cycle repeats.
As far as targeting dolphin/billfish two miles out of Key West -- I don't think so... You need to run through Hawks Channel out to the reef line; and that'll vary with your direction -- but plan on at least 6 miles.
Grouper season is closed, but Mutton Snapper are available. If you can get offshore to the Gulf Stream, almost anything is possible.
If I were you, I'd leave the boat home and save some $$ to hire a guide for one day trip reef fishing. Contact Rob at Conchy Joe's Tackle in Key West and he can book something for you.
PB