Magnus...the Dominican Republic /Luperon is a destination after the Bahamas which would give them some Spanish. There would be no "Easting" involved and just one overnight sail to get there after island hopping down the Bahamas to the Turks & Caicos. The problem is conditions in Luperon.
We found Luperon very dirty and unsanitary, officials somewhat corrupt and provisioning meager...really third world environment. BUT...the people are friendly enough and they do speak Spanish and you can take road tours to the other side of the island and Santo Domingo which is a nice city and full of history. Whether you want to place your kids in this environment is the question. You might private message Sialia who had his family there with him a couple of yeas back for his perspective on this.
-I think you can spend months seeing the Abacos and Exumas and the Bahama out islands and the kids will never tire of it.
-You should see and do the ICW once if you never have. A beautiful and interesting trip with lots of neat places from cities like Savannah/Charleston to incredible preserves like Cumberland island. November 1st or thereabouts is not too late to head down in comfort . If you have a cockpit enclosure...even better. But you don't need heat on board to do it...just sleeping bags or blankets till you get a bit south. From Norfolk it is easily done in one month with time off to see stuff.
-If you want to do Mexico as well...I would head back from the Bahamas to the Miami area and do the Keys to Key West. Then on a good forecast, leave from Key West to IslaMujueres which should be a 3-4 day trip in the Gulf. There is another recent thread covering this trip but it is obviously quite easily do-able in the time you have.
-You might check on some of Steve Pavlidas's threads over on SSCA.org if you are interested to Jamaica/Cayman/Belize. He is currently aboard in Belize and working on publishing a new guide to the Western Caribe and is most generous with his expertise.