Richard, as I see it, the big lesson learned here is not to book non-refundable air until you are absolutely sure of your land booking. I don't agree, however, that a TA is the answer to everything. Ngaire and her company are highly specialized, have personally experienced each and every property they sell. Land resorts still use TA's as I know. The TA books you, and receives a commission from the property, but that doesn't mean that the TA has been there, just that you have a "possible" remedy. I think with land travel, there is no substitute for "due diligence" and researching on your own, and with the internet, there is so much information out there! I have booked all my own land travel personally over the past few years, and have never been disappointed. Recent land trips other than cruises through BK include The Reefs in Bermuda, Pink Sands in Harbour Island in the Bahamas, Little Palm Island in the Florida Keys, and a condo in Playa del Carmen. I did extensive research on each, as I know what I want (A Regent experience!). But they were not free!
To answer your last question, I put that thing together in the Florida Keys on my own in two days right before we were scheduled to leave. My daughter Jes had a passport problem, so we couldn't go to Anguilla as planned. She found the hotel (knowing what I look for), it looked great to me, and we had a wonderful time! You are going to be way off season, with openings everywhere! I say go for it and plan something on your own. But you will pay for it. Going back within a year may not bring you a better result than you have now!