My memory may be hazy, but this sitcom was about a single dad who moved his family to Florida. The actor who played the dad was a gruff character actor, and the kids ranged in age from little to teenagers (I believe about 6 kids in all). I think the series was a summer replacement, and only lasted about a dozen episodes. Anyone remember its name?

Maybe it was: "I Married Dora". :confused: This premiered in the fall of 1987 and starred Elizabeth Pena, who recently had starred in the blockboster movie, "La Bamba". The premise was this widowed dad who hired this housekeeper (Pena) and marries her so she won't get deported.

This may be a longshot since it is

not a sitcom
not from the 80s
not set in Florida
technically not featuring a single *father*

yet it is the only show I can think of that at all resembles your description:
The Mackenzies of Paradise Cove
airing March 28, 1979 - May 18, 1979 on ABC. Five kids ranging in age from 7 to 17 lost their parents in a sailing accident and conned a fishing-boat operator into posing as their uncle so that they could all stay together. The show was set in Hawaii and very briefly replaced Eight Is Enough on Wednesdays (it was an hour long), then replaced Family on Fridays, then disappeared forever.