Just so you know, all of the diving in the Keys is off boats.
If you're looking for shore diving, you can find some of the best in the SE USA very near Ft Lauderdale at Lauderdale by the Sea. If you are interested in shore diving, check out Gold Coast Scuba's Meetup.com dive group. The shop is a good one and the dive group is very active.
Sportxlh is right on target.
For shore dives ....Stay north near Pompano Beach, Lauderdale by the sea, or Ft Lauderdale. However, finding a buddy could be a big challenge too, so the meetup.com suggestion I suppose, (never tried it) is good suggestion.
Keep in mind that if the weather gets nasty, conditions from the shore will not be pretty either. And November WX can sometimes be very windy & rough in SE FL.
Suggestion: Have a back up plan that incudes mommy and the 4 year old, so you all have fun. Suggestion: Consider a tram ride (lots of alligators if you cycle with the 4 year old) Shark valley in the everglades:
Shark Valley Visitor Center - Everglades National Park (U.S. National Park Service)
Here's another suggestion...drive to Everglades City and buy Stone Crabs right off the boats (after they have been cooked). Go to Everglades National park and eat them, this has been an annual ritual for my wife and I for the last 20 years or so. This is where we get them:
Grimm Stone Crab- Fresh Florida Stone Crab Shipped,
Hope this helps. If any questions, keep asking...your with a good group here.
If you elect to hit the Keyes and use a dive boat, first consult with your physician to see if you can take a seasick Med while scuba diving. That may mitigate or solve your boat dive sea sick issues and your dive buddy concerns. Again, November WX can be rough, calm or something in between.
The good news is you are going to be in a beautiful sub-tropical paradise with great people, good food and a lot of good things to see, even if you are limited to on land stuff.
If you head south towards the Keyes, consider visiting the Coral Castle
Coral Castle Museum (about an hour out of your life) and have lunch at
Casavana Cuban Cuisine | A new family restaurant serving homestyle Cuban favorites and much more. (great Cuban food...and the Cuban people are wonderful) which is somewhat nearby.
IMO, particularly if time is short, you don't need to go much further than Key Largo to experience the enjoyable "slow down" time warp in the Keyes.